C
program examples (TOTAL 90 programs)
Example 1 - C hello world
program
/** My first c program */
/** My first c program */
#include
<stdio.h>
int main()
{
printf("Hello World\n");
return 0;
}
Output of above program:
"Hello World"
"Hello World"
Example 2 - c program to
take input from user using scanf
#include
<stdio.h>
main()
{
int number;
printf("Enter an integer\n");
scanf("%d",&number);
printf("Integer entered by
you is %d\n", number);
return 0;
}
Output:
Enter a number
5
Number entered by you is 5
Enter a number
5
Number entered by you is 5
Example 3 - using if else
control instructions
#include
<stdio.h>
main()
{
int x = 1;
if ( x == 1 )
printf("x is equal to one.\n");
else
printf("For comparison use
== as = is the assignment operator.\n");
return 0;
}
Output:
x is equal to one.
x is equal to one.
Example 4 - loop example
#include
<stdio.h>
main()
{
int value = 1;
while(value<=3)
{
printf("Value is %d\n", value);
value++;
}
return 0;
}
Output:
Value is 1
Value is 2
Value is 3
Value is 1
Value is 2
Value is 3
Example 5 - c program for
prime number
#include
<stdio.h>
main()
{
int n, c;
printf("Enter a number\n");
scanf("%d", &n);
if ( n == 2 )
printf("Prime number.\n");
else
{
for ( c = 2 ; c <= n - 1 ; c++ )
{
if ( n % c == 0 )
break;
}
if ( c != n )
printf("Not prime.\n");
else
printf("Prime number.\n");
}
return 0;
}
Example 6 - command line
arguments
#include
<stdio.h>
main(int argc, char *argv[])
{
int c;
printf("Number of command
line arguments passed: %d\n", argc);
for ( c = 0 ; c < argc ; c++)
printf("%d. Command line
argument passed is %s\n", c+1, argv[c]);
return 0;
}
Above c program prints
the number and all arguments which are passed to it.
Example 7 - Array program
#include
<stdio.h>
main()
{
int array[100], n, c;
printf("Enter the number of
elements in array\n");
scanf("%d", &n);
printf("Enter %d elements\n", n);
for ( c = 0 ; c < n ; c++ )
scanf("%d", &array[c]);
printf("Array elements
entered by you are:\n");
for ( c = 0 ; c < n ; c++ )
printf("array[%d] = %d\n", c, array[c]);
return 0;
}
Example 8 - function
program
#include
<stdio.h>
void my_function();
main()
{
printf("Main function.\n");
my_function();
printf("Back in function
main.\n");
return 0;
}
void my_function()
{
printf("Welcome to my
function. Feel at home.\n");
}
Example 9 - Using
comments in a program
#include
<stdio.h>
main()
{
//
Single line comment in c source code
printf("Writing comments is
very useful.\n");
/*
* Multi line comment syntax
* Comments help us to understand code later
easily.
* Will you write comments while developing
programs ?
*/
printf("Good luck c
programmer.\n");
return 0;
}
Example 10 - using
structures in c programming
#include
<stdio.h>
struct programming
{
float constant;
char *pointer;
};
main()
{
struct programming variable;
char string[] = "Programming in
Software Development.";
variable.constant = 1.23;
variable.pointer = string;
printf("%f\n", variable.constant);
printf("%s\n", variable.pointer);
return 0;
}
Example 11 - c program
for Fibonacci series
#include <stdio.h>
main()
{
int n, first = 0, second = 1, next, c;
printf("Enter the number of
terms\n");
scanf("%d",&n);
printf("First %d terms of
Fibonacci series are :-\n",n);
for ( c = 0 ; c < n ; c++ )
{
if ( c <= 1 )
next = c;
else
{
next = first + second;
first = second;
second = next;
}
printf("%d\n",next);
}
return 0;
}
C program to store integer in a string
#include <stdio.h>
int main ()
{
char n[1000];
printf("Input an integer\n");
scanf("%s", n);
printf("%s", n);
return 0;
}
Output of program:
Input an integer
13246523123156432123154131212341564313219
13246523123156432123154131212341564313219
#include<stdio.h>
int main()
{
int a, b, c;
printf("Enter two numbers to add\n");
scanf("%d%d",&a,&b);
c = a + b;
printf("Sum of entered numbers = %d\n",c);
return 0;
}
Addition without using third variable
#include<stdio.h>
main()
{
int a = 1, b = 2;
/* Storing result of addition in variable a */
a = a + b;
/** Not recommended because original value of a is lost
* and you may be using it somewhere in code considering it
* as it was entered by the user.
*/
printf("Sum of a and b = %d\n", a);
return 0;
}
C program to add two numbers repeatedly
#include <stdio.h>
int main()
{
int a, b, c;
char ch;
while (1) {
printf("Inut two integers\n");
scanf("%d%d", &a, &b);
getchar();
c = a + b;
printf("(%d) + (%d) = (%d)\n", a, b, c);
printf("Do you wish to add more numbers (y/n)\n");
scanf("%c", &ch);
if (ch == 'y' || ch == 'Y')
continue;
else
break;
}
return 0;
}
Output of program:
Inut two integers
2 6
(2) + (6) = (8)
Do you wish to add more numbers (y/n)
y
Inut two integers
2 -6
(2) + (-6) = (-4)
Do you wish to add more numbers (y/n)
y
Inut two integers
-5 3
(-5) + (3) = (-2)
Do you wish to add more numbers (y/n)
y
Inut two integers
-5 -6
(-5) + (-6) = (-11)
Do you wish to add more numbers (y/n)
n
Adding numbers in c using function
#include<stdio.h>
long addition(long, long);
main()
{
long first, second, sum;
scanf("%ld%ld", &first, &second);
sum = addition(first, second);
printf("%ld\n", sum);
return 0;
}
long addition(long a, long b)
{
long result;
result = a + b;
return result;
}
C program to check odd or even using modulus operator
#include <stdio.h>
int main()
{
int n;
printf("Enter an integer\n");
scanf("%d", &n);
if (n%2 == 0)
printf("Even\n");
else
printf("Odd\n");
return 0;
}
We can use bitwise AND (&) operator to check odd or even, as
an example consider binary of 7 (0111) when we perform 7 & 1 the result
will be one and you may observe that the least significant bit of every odd
number is 1, so ( odd_number & 1 ) will be one always and also (
even_number & 1 ) is zero.
C program to check odd or even using bitwise operator
#include <stdio.h>
int main()
{
int n;
printf("Enter an integer\n");
scanf("%d", &n);
if (n & 1 == 1)
printf("Odd\n");
else
printf("Even\n");
return 0;
}
Find odd or even using conditional operator
#include <stdio.h>
int main()
{
int n;
printf("Input an integer\n");
scanf("%d", &n);
n%2 == 0 ? printf("Even\n") : printf("Odd\n");
return 0;
}
C program to check odd or even without using bitwise or modulus
operator
#include <stdio.h>
int main()
{
int n;
printf("Enter an integer\n");
scanf("%d", &n);
if ((n/2)*2 == n)
printf("Even\n");
else
printf("Odd\n");
return 0;
}
This code checks whether an input alphabet is a vowel or not.
Both lower-case and upper-case are checked.
C programming code
#include <stdio.h>
int main()
{
char ch;
printf("Enter a character\n");
scanf("%c", &ch);
if (ch == 'a' || ch == 'A' || ch == 'e' || ch == 'E' || ch == 'i' || ch == 'I' || ch =='o' || ch=='O' || ch == 'u' || ch == 'U')
printf("%c is a vowel.\n", ch);
else
printf("%c is not a vowel.\n", ch);
return 0;
}
Check vowel using switch statement
#include <stdio.h>
int main()
{
char ch;
printf("Input a character\n");
scanf("%c", &ch);
switch(ch)
{
case 'a':
case 'A':
case 'e':
case 'E':
case 'i':
case 'I':
case 'o':
case 'O':
case 'u':
case 'U':
printf("%c is a vowel.\n", ch);
break;
default:
printf("%c is not a vowel.\n", ch);
}
return 0;
}
Function
to check vowel
int check_vowel(char a)
{
if (a >= 'A' && a <= 'Z')
a = a + 'a' - 'A'; /* Converting to lower case or use a = a + 32 */
if (a == 'a' || a == 'e' || a == 'i' || a == 'o' || a == 'u')
return 1;
return 0;
}
C program to check leap year: c code to check leap year, year
will be entered by the user.
C programming code
#include <stdio.h>
int main()
{
int year;
printf("Enter a year to check if it is a leap year\n");
scanf("%d", &year);
if ( year%400 == 0)
printf("%d is a leap year.\n", year);
else if ( year%100 == 0)
printf("%d is not a leap year.\n", year);
else if ( year%4 == 0 )
printf("%d is a leap year.\n", year);
else
printf("%d is not a leap year.\n", year);
return 0;
}
C program to add digits of a number: Here we are using modulus
operator(%) to extract individual digits of number and adding them.
C programming code
#include <stdio.h>
int main()
{
int n, t, sum = 0, remainder;
printf("Enter an integer\n");
scanf("%d", &n);
t = n;
while (t != 0)
{
remainder = t % 10;
sum = sum + remainder;
t = t / 10;
}
printf("Sum of digits of %d = %d\n", n, sum);
return 0;
}
Factorial program in c using for loop
Here we find factorial using for loop.
#include <stdio.h>
int main()
{
int c, n, fact = 1;
printf("Enter a number to calculate it's factorial\n");
scanf("%d", &n);
for (c = 1; c <= n; c++)
fact = fact * c;
printf("Factorial of %d = %d\n", n, fact);
return 0;
}
C programming code
#include <stdio.h>
int main() {
int a, b, x, y, t, gcd, lcm;
printf("Enter two integers\n");
scanf("%d%d", &x, &y);
a = x;
b = y;
while (b != 0) {
t = b;
b = a % b;
a = t;
}
gcd = a;
lcm = (x*y)/gcd;
printf("Greatest common divisor of %d and %d = %d\n", x, y, gcd);
printf("Least common multiple of %d and %d = %d\n", x, y, lcm);
return 0;
}
Decimal
to binary conversion
#include <stdio.h>
int main()
{
int n, c, k;
printf("Enter an integer in decimal number system\n");
scanf("%d", &n);
printf("%d in binary number system is:\n", n);
for (c = 31; c >= 0; c--)
{
k = n >> c;
if (k & 1)
printf("1");
else
printf("0");
}
printf("\n");
return 0;
}
C
program to add n numbers
#include <stdio.h>
int main()
{
int n, sum = 0, c, value;
printf("Enter the number of integers you want to add\n");
scanf("%d", &n);
printf("Enter %d integers\n",n);
for (c = 1; c <= n; c++)
{
scanf("%d", &value);
sum = sum + value;
}
printf("Sum of entered integers = %d\n",sum);
return 0;
}
C programming code using array
#include <stdio.h>
int main()
{
int n, sum = 0, c, array[100];
scanf("%d", &n);
for (c = 0; c < n; c++)
{
scanf("%d", &array[c]);
sum = sum + array[c];
}
printf("Sum = %d\n",sum);
return 0;
}
The advantage of using array is that we have a record of numbers
inputted by user and can use them further in program if required and obviously
storing numbers will require additional memory.
Add n numbers using recursion
#include <stdio.h>
long calculateSum(int [], int);
int main()
{
int n, c, array[100];
long result;
scanf("%d", &n);
for (c = 0; c < n; c++)
scanf("%d", &array[c]);
result = calculateSum(array, n);
printf("Sum = %ld\n", result);
return 0;
}
long calculateSum(int a[], int n) {
static long sum = 0;
if (n == 0)
return sum;
sum = sum + a[n-1];
return calculateSum(a, --n);
}
Swapping of two numbers in c
#include <stdio.h>
int main()
{
int x, y, temp;
printf("Enter the value of x and y\n");
scanf("%d%d", &x, &y);
printf("Before Swapping\nx = %d\ny = %d\n",x,y);
temp = x;
x = y;
y = temp;
printf("After Swapping\nx = %d\ny = %d\n",x,y);
return 0;
}
Swapping of two numbers without third variable
You can also swap two numbers without using temp or temporary or third
variable. In that case c program will be as shown :-
#include <stdio.h>
int main()
{
int a, b;
printf("Enter two integers to swap\n");
scanf("%d%d", &a, &b);
a = a + b;
b = a - b;
a = a - b;
printf("a = %d\nb = %d\n",a,b);
return 0;
}
To understand above logic simply choose a as 7 and b as 9 and
then do what is written in program. You can choose any other combination of
numbers as well. Sometimes it's a good way to understand a program.
Swap two numbers using pointers
#include <stdio.h>
int main()
{
int x, y, *a, *b, temp;
printf("Enter the value of x and y\n");
scanf("%d%d", &x, &y);
printf("Before Swapping\nx = %d\ny = %d\n", x, y);
a = &x;
b = &y;
temp = *b;
*b = *a;
*a = temp;
printf("After Swapping\nx = %d\ny = %d\n", x, y);
return 0;
}
Swapping numbers using call by reference
In this method we will make a function to swap numbers.
#include <stdio.h>
void swap(int*, int*);
int main()
{
int x, y;
printf("Enter the value of x and y\n");
scanf("%d%d",&x,&y);
printf("Before Swapping\nx = %d\ny = %d\n", x, y);
swap(&x, &y);
printf("After Swapping\nx = %d\ny = %d\n", x, y);
return 0;
}
void swap(int *a, int *b)
{
int temp;
temp = *b;
*b = *a;
*a = temp;
}
C programming code to swap using bitwise XOR
#include <stdio.h>
int main()
{
int x, y;
scanf("%d%d", &x, &y);
printf("x = %d\ny = %d\n", x, y);
x = x ^ y;
y = x ^ y;
x = x ^ y;
printf("x = %d\ny = %d\n", x, y);
return 0;
}
C
program to reverse a number
#include <stdio.h>
int main()
{
int n, reverse = 0;
printf("Enter a number to reverse\n");
scanf("%d", &n);
while (n != 0)
{
reverse = reverse * 10;
reverse = reverse + n%10;
n = n/10;
}
printf("Reverse of entered number is = %d\n", reverse);
return 0;
}
C program to reverse number using recursion
#include <stdio.h>
long reverse(long);
int main()
{
long n, r;
scanf("%ld", &n);
r = reverse(n);
printf("%ld\n", r);
return 0;
}
long reverse(long n) {
static long r = 0;
if (n == 0)
return 0;
r = r * 10;
r = r + n % 10;
reverse(n/10);
return r;
}
Palindrome number algorithm
1. Get the number from user.
2. Reverse it.
3. Compare it with the number entered by the user.
4. If both are same then print palindrome number
5. Else print not a palindrome number.
2. Reverse it.
3. Compare it with the number entered by the user.
4. If both are same then print palindrome number
5. Else print not a palindrome number.
Palindrome number program c
#include <stdio.h>
int main()
{
int n, reverse = 0, temp;
printf("Enter a number to check if it is a palindrome or not\n");
scanf("%d",&n);
temp = n;
while( temp != 0 )
{
reverse = reverse * 10;
reverse = reverse + temp%10;
temp = temp/10;
}
if ( n == reverse )
printf("%d is a palindrome number.\n", n);
else
printf("%d is not a palindrome number.\n", n);
return 0;
}
PRINT PATTERNS
*
***
*****
*******
*********
We have shown five rows above, in the program you will be asked
to enter the numbers of rows you want to print in the pyramid of stars.
C programming code
#include <stdio.h>
int main()
{
int row, c, n, temp;
printf("Enter the number of rows in pyramid of stars you wish to see ");
scanf("%d",&n);
temp = n;
for ( row = 1 ; row <= n ; row++ )
{
for ( c = 1 ; c < temp ; c++ )
printf(" ");
temp--;
for ( c = 1 ; c <= 2*row - 1 ; c++ )
printf("*");
printf("\n");
}
return 0;
}
Prime number program in c language
#include<stdio.h>
int main()
{
int n, i = 3, count, c;
printf("Enter the number of prime numbers required\n");
scanf("%d",&n);
if ( n >= 1 )
{
printf("First %d prime numbers are :\n",n);
printf("2\n");
}
for ( count = 2 ; count <= n ; )
{
for ( c = 2 ; c <= i - 1 ; c++ )
{
if ( i%c == 0 )
break;
}
if ( c == i )
{
printf("%d\n",i);
count++;
}
i++;
}
return 0;
}
Armstrong
number c program
Armstrong number c program: c programming code to check whether
a number is Armstrong or not. Armstrong number is a number which is equal to
sum of digits raise to the power total number of digits in the number. Some
Armstrong numbers are: 0, 1, 2, 3, 153, 370, 407, 1634, 8208 etc. Read more
about Armstrong numbers at Wikipedia. We will
consider base 10 numbers in our program. Algorithm to check Armstrong is: First
we calculate number of digits in our program and then compute sum of individual
digits raise to the power number of digits. If this sum equals input number
then number is Armstrong otherwise not an Armstrong number.
Examples:
7 = 7^1
371 = 3^3 + 7^3 + 1^3 (27 + 343 +1)
8208 = 8^4 + 2^4 +0^4 + 8^4 (4096 + 16 + 0 + 4096).
1741725 = 1^7 + 7^7 + 4^7 + 1^7 + 7^7 + 2^7 +5^7 (1 + 823543 + 16384 + 1 + 823543 +128 + 78125)
7 = 7^1
371 = 3^3 + 7^3 + 1^3 (27 + 343 +1)
8208 = 8^4 + 2^4 +0^4 + 8^4 (4096 + 16 + 0 + 4096).
1741725 = 1^7 + 7^7 + 4^7 + 1^7 + 7^7 + 2^7 +5^7 (1 + 823543 + 16384 + 1 + 823543 +128 + 78125)
C programming code
#include <stdio.h>
int power(int, int);
int main()
{
int n, sum = 0, temp, remainder, digits = 0;
printf("Input an integer\n");
scanf("%d", &n);
temp = n;
// Count number of digits
while (temp != 0) {
digits++;
temp = temp/10;
}
temp = n;
while (temp != 0) {
remainder = temp%10;
sum = sum + power(remainder, digits);
temp = temp/10;
}
if (n == sum)
printf("%d is an Armstrong number.\n", n);
else
printf("%d is not an Armstrong number.\n", n);
return 0;
}
int power(int n, int r) {
int c, p = 1;
for (c = 1; c <= r; c++)
p = p*n;
return p;
C
program to generate and print armstrong numbers
C program to generate Armstrong numbers. In our program user
will input two integers and we will print all Armstrong numbers between two
integers. Using a for loop we will check numbers in the desired range. In our
loop we call our function check_armstrong which returns 1 if number is Armstrong
and 0 otherwise. If you are not familiar with Armstrong numbers see Check Armstrong number program.
C programming code
#include <stdio.h>
int check_armstrong(int);
int power(int, int);
int main () {
int c, a, b;
printf("Input two integers\n");
scanf("%d%d", &a, &b);
for (c = a; c <= b; c++) {
if (check_armstrong(c) == 1)
printf("%d\n", c);
}
return 0;
}
int check_armstrong(int n) {
long long sum = 0, temp;
int remainder, digits = 0;
temp = n;
while (temp != 0) {
digits++;
temp = temp/10;
}
temp = n;
while (temp != 0) {
remainder = temp%10;
sum = sum + power(remainder, digits);
temp = temp/10;
}
if (n == sum)
return 1;
else
return 0;
}
int power(int n, int r) {
int c, p = 1;
for (c = 1; c <= r; c++)
p = p*n;
return p;
}
Fibonacci series in c using for loop
/* Fibonacci Series c language */
#include<stdio.h>
int main()
{
int n, first = 0, second = 1, next, c;
printf("Enter the number of terms\n");
scanf("%d",&n);
printf("First %d terms of Fibonacci series are :-\n",n);
for ( c = 0 ; c < n ; c++ )
{
if ( c <= 1 )
next = c;
else
{
next = first + second;
first = second;
second = next;
}
printf("%d\n",next);
}
return 0;
}
Fibonacci series program in c using recursion
#include<stdio.h>
int Fibonacci(int);
main()
{
int n, i = 0, c;
scanf("%d",&n);
printf("Fibonacci series\n");
for ( c = 1 ; c <= n ; c++ )
{
printf("%d\n", Fibonacci(i));
i++;
}
return 0;
}
int Fibonacci(int n)
{
if ( n == 0 )
return 0;
else if ( n == 1 )
return 1;
else
return ( Fibonacci(n-1) + Fibonacci(n-2) );
}
C
program to print Floyd's triangle
C program to print Floyd's triangle:- This program prints
Floyd's triangle. Number of rows of Floyd's triangle to print is entered by the
user. First four rows of Floyd's triangle are as follows :-
1
2 3
4 5 6
7 8 9 10
It's clear that in Floyd's triangle nth row contains n numbers.
1
2 3
4 5 6
7 8 9 10
It's clear that in Floyd's triangle nth row contains n numbers.
C programming code
#include <stdio.h>
int main()
{
int n, i, c, a = 1;
printf("Enter the number of rows of Floyd's triangle to print\n");
scanf("%d", &n);
for (i = 1; i <= n; i++)
{
for (c = 1; c <= i; c++)
{
printf("%d ",a);
a++;
}
printf("\n");
}
return 0;
}
C
program to print Pascal triangle
Pascal Triangle in c: C program to print Pascal triangle which
you might have studied in Binomial Theorem in Mathematics. Number of rows of
Pascal triangle to print is entered by the user. First four rows of Pascal
triangle are shown below :-
1
1 1
1 2 1
1 3 3 1
Pascal triangle in c
#include <stdio.h>
long factorial(int);
int main()
{
int i, n, c;
printf("Enter the number of rows you wish to see in pascal triangle\n");
scanf("%d",&n);
for (i = 0; i < n; i++)
{
for (c = 0; c <= (n - i - 2); c++)
printf(" ");
for (c = 0 ; c <= i; c++)
printf("%ld ",factorial(i)/(factorial(c)*factorial(i-c)));
printf("\n");
}
return 0;
}
long factorial(int n)
{
int c;
long result = 1;
for (c = 1; c <= n; c++)
result = result*c;
return result;
}
C
program to add two numbers using pointers
This program performs addition of two numbers using pointers. In
our program we have two two integer variables x, y and two pointer variables p
and q. Firstly we assign the addresses of x and y to p and q respectively and
then assign the sum of x and y to variable sum. Note that & is address of
operator and * is value at address operator.
C programming code
#include <stdio.h>
int main()
{
int first, second, *p, *q, sum;
printf("Enter two integers to add\n");
scanf("%d%d", &first, &second);
p = &first;
q = &second;
sum = *p + *q;
printf("Sum of entered numbers = %d\n",sum);
return 0;
}
Output of program:
C program to add numbers using call by reference
#include <stdio.h>
long add(long *, long *);
int main()
{
long first, second, *p, *q, sum;
printf("Input two integers to add\n");
scanf("%ld%ld", &first, &second);
sum = add(&first, &second);
printf("(%ld) + (%ld) = (%ld)\n", first, second, sum);
return 0;
}
long add(long *x, long *y) {
long sum;
sum = *x + *y;
return sum;
}
C
program to find hcf and lcm
C program to find hcf and lcm: The code below finds highest
common factor and least common multiple of two integers. HCF is also known as
greatest common divisor(GCD) or greatest common factor(gcf).
C programming code
#include <stdio.h>
int main() {
int a, b, x, y, t, gcd, lcm;
printf("Enter two integers\n");
scanf("%d%d", &x, &y);
a = x;
b = y;
while (b != 0) {
t = b;
b = a % b;
a = t;
}
gcd = a;
lcm = (x*y)/gcd;
printf("Greatest common divisor of %d and %d = %d\n", x, y, gcd);
printf("Least common multiple of %d and %d = %d\n", x, y, lcm);
return 0;
}
Linear search c program
#include <stdio.h>
int main()
{
int array[100], search, c, n;
printf("Enter the number of elements in array\n");
scanf("%d",&n);
printf("Enter %d integer(s)\n", n);
for (c = 0; c < n; c++)
scanf("%d", &array[c]);
printf("Enter the number to search\n");
scanf("%d", &search);
for (c = 0; c < n; c++)
{
if (array[c] == search) /* if required element found */
{
printf("%d is present at location %d.\n", search, c+1);
break;
}
}
if (c == n)
printf("%d is not present in array.\n", search);
return 0;
}
C
program to reverse an array
C program to reverse an array: This program reverses the array
elements. For example if a is an array of integers with three elements such
that
a[0] = 1
a[1] = 2
a[2] = 3
Then on reversing the array will be
a[0] = 3
a[1] = 2
a[0] = 1
a[0] = 1
a[1] = 2
a[2] = 3
Then on reversing the array will be
a[0] = 3
a[1] = 2
a[0] = 1
Given below is the c code to reverse an array.
C programming code
#include <stdio.h>
int main()
{
int n, c, d, a[100], b[100];
printf("Enter the number of elements in array\n");
scanf("%d", &n);
printf("Enter the array elements\n");
for (c = 0; c < n ; c++)
scanf("%d", &a[c]);
/*
* Copying elements into array b starting from end of array a
*/
for (c = n - 1, d = 0; c >= 0; c--, d++)
b[d] = a[c];
/*
* Copying reversed array into original.
* Here we are modifying original array, this is optional.
*/
for (c = 0; c < n; c++)
a[c] = b[c];
printf("Reverse array is\n");
for (c = 0; c < n; c++)
printf("%d\n", a[c]);
return 0;
}
C
program to insert an element in an array
This code will insert an element into an array, For example
consider an array a[10] having three elements in it initially and a[0] = 1,
a[1] = 2 and a[2] = 3 and you want to insert a number 45 at location 1 i.e.
a[0] = 45, so we have to move elements one step below so after insertion a[1] =
1 which was a[0] initially, and a[2] = 2 and a[3] = 3. Array insertion does not
mean increasing its size i.e array will not be containing 11 elements.
C programming code
#include <stdio.h>
int main()
{
int array[100], position, c, n, value;
printf("Enter number of elements in array\n");
scanf("%d", &n);
printf("Enter %d elements\n", n);
for (c = 0; c < n; c++)
scanf("%d", &array[c]);
printf("Enter the location where you wish to insert an element\n");
scanf("%d", &position);
printf("Enter the value to insert\n");
scanf("%d", &value);
for (c = n - 1; c >= position - 1; c--)
array[c+1] = array[c];
array[position-1] = value;
printf("Resultant array is\n");
for (c = 0; c <= n; c++)
printf("%d\n", array[c]);
return 0;
}
Bubble sort algorithm in c
/* Bubble sort code */
#include <stdio.h>
int main()
{
int array[100], n, c, d, swap;
printf("Enter number of elements\n");
scanf("%d", &n);
printf("Enter %d integers\n", n);
for (c = 0; c < n; c++)
scanf("%d", &array[c]);
for (c = 0 ; c < ( n - 1 ); c++)
{
for (d = 0 ; d < n - c - 1; d++)
{
if (array[d] > array[d+1]) /* For decreasing order use < */
{
swap = array[d];
array[d] = array[d+1];
array[d+1] = swap;
}
}
}
printf("Sorted list in ascending order:\n");
for ( c = 0 ; c < n ; c++ )
printf("%d\n", array[c]);
return 0;
}
Selection sort algorithm implementation in c
#include <stdio.h>
int main()
{
int array[100], n, c, d, position, swap;
printf("Enter number of elements\n");
scanf("%d", &n);
printf("Enter %d integers\n", n);
for ( c = 0 ; c < n ; c++ )
scanf("%d", &array[c]);
for ( c = 0 ; c < ( n - 1 ) ; c++ )
{
position = c;
for ( d = c + 1 ; d < n ; d++ )
{
if ( array[position] > array[d] )
position = d;
}
if ( position != c )
{
swap = array[c];
array[c] = array[position];
array[position] = swap;
}
}
printf("Sorted list in ascending order:\n");
for ( c = 0 ; c < n ; c++ )
printf("%d\n", array[c]);
return 0;
}
C
program to add two matrix
This c program add two matrices i.e. compute the sum of two
matrices and then print it. Firstly user will be asked to enter the order of
matrix (number of rows and columns) and then two matrices. For example if the
user entered order as 2, 2 i.e. two rows and two columns and matrices as
First Matrix :-
1 2
3 4
Second matrix :-
4 5
-1 5
then output of the program (sum of First and Second matrix) will be
5 7
2 9
First Matrix :-
1 2
3 4
Second matrix :-
4 5
-1 5
then output of the program (sum of First and Second matrix) will be
5 7
2 9
C programming code
#include <stdio.h>
int main()
{
int m, n, c, d, first[10][10], second[10][10], sum[10][10];
printf("Enter the number of rows and columns of matrix\n");
scanf("%d%d", &m, &n);
printf("Enter the elements of first matrix\n");
for (c = 0; c < m; c++)
for (d = 0; d < n; d++)
scanf("%d", &first[c][d]);
printf("Enter the elements of second matrix\n");
for (c = 0; c < m; c++)
for (d = 0 ; d < n; d++)
scanf("%d", &second[c][d]);
printf("Sum of entered matrices:-\n");
for (c = 0; c < m; c++) {
for (d = 0 ; d < n; d++) {
sum[c][d] = first[c][d] + second[c][d];
printf("%d\t", sum[c][d]);
}
printf("\n");
}
return 0;
}
C
program to transpose a matrix
This c program prints transpose of a matrix. It is obtained by
interchanging rows and columns of a matrix. For example if a matrix is
1 2
3 4
5 6
then transpose of above matrix will be
1 3 5
2 4 6
When we transpose a matrix then the order of matrix changes, but for a square matrix order remains same.
1 2
3 4
5 6
then transpose of above matrix will be
1 3 5
2 4 6
When we transpose a matrix then the order of matrix changes, but for a square matrix order remains same.
C programming code
#include <stdio.h>
int main()
{
int m, n, c, d, matrix[10][10], transpose[10][10];
printf("Enter the number of rows and columns of matrix\n");
scanf("%d%d", &m, &n);
printf("Enter the elements of matrix\n");
for (c = 0; c < m; c++)
for(d = 0; d < n; d++)
scanf("%d",&matrix[c][d]);
for (c = 0; c < m; c++)
for( d = 0 ; d < n ; d++ )
transpose[d][c] = matrix[c][d];
printf("Transpose of entered matrix :-\n");
for (c = 0; c < n; c++) {
for (d = 0; d < m; d++)
printf("%d\t",transpose[c][d]);
printf("\n");
}
return 0;
}
Matrix
multiplication in c
Matrix multiplication in c language: c program to multiply
matrices (two dimensional array), this program multiplies two matrices which
will be entered by the user. Firstly user will enter the order of a matrix. If
the entered orders of two matrix is such that they can't be multiplied then an
error message is displayed on the screen. You have already studied the logic to
multiply them in Mathematics.
Matrix multiplication in c language
#include <stdio.h>
int main()
{
int m, n, p, q, c, d, k, sum = 0;
int first[10][10], second[10][10], multiply[10][10];
printf("Enter the number of rows and columns of first matrix\n");
scanf("%d%d", &m, &n);
printf("Enter the elements of first matrix\n");
for (c = 0; c < m; c++)
for (d = 0; d < n; d++)
scanf("%d", &first[c][d]);
printf("Enter the number of rows and columns of second matrix\n");
scanf("%d%d", &p, &q);
if (n != p)
printf("Matrices with entered orders can't be multiplied with each other.\n");
else
{
printf("Enter the elements of second matrix\n");
for (c = 0; c < p; c++)
for (d = 0; d < q; d++)
scanf("%d", &second[c][d]);
for (c = 0; c < m; c++) {
for (d = 0; d < q; d++) {
for (k = 0; k < p; k++) {
sum = sum + first[c][k]*second[k][d];
}
multiply[c][d] = sum;
sum = 0;
}
}
printf("Product of entered matrices:-\n");
for (c = 0; c < m; c++) {
for (d = 0; d < q; d++)
printf("%d\t", multiply[c][d]);
printf("\n");
}
}
return 0;
}
C program to find string length
#include <stdio.h>
#include <string.h>
int main()
{
char a[100];
int length;
printf("Enter a string to calculate it's length\n");
gets(a);
length = strlen(a);
printf("Length of entered string is = %d\n",length);
return 0;
}
C program to compare two strings using strcmp
#include <stdio.h>
#include <string.h>
int main()
{
char a[100], b[100];
printf("Enter the first string\n");
gets(a);
printf("Enter the second string\n");
gets(b);
if (strcmp(a,b) == 0)
printf("Entered strings are equal.\n");
else
printf("Entered strings are not equal.\n");
return 0;
}
Function strcmp is case sensitive and returns 0 if both strings
are equal.
Output of program:
C program to compare two strings without using strcmp
Here we create our own function to compare strings.
#include <stdio.h>
int compare_strings(char [], char []);
int main()
{
int flag;
char a[1000], b[1000];
printf("Input first string\n");
gets(a);
printf("Input second string\n");
gets(b);
flag = compare_strings(a, b);
if (flag == 0)
printf("Entered strings are equal.\n");
else
printf("Entered strings are not equal.\n");
return 0;
}
int compare_strings(char a[], char b[])
{
int c = 0;
while (a[c] == b[c]) {
if (a[c] == '\0' || b[c] == '\0')
break;
c++;
}
if (a[c] == '\0' && b[c] == '\0')
return 0;
else
return -1;
}
String
copying in c programming
This program copy string using library function strcpy, to copy
string without using strcpy see source code below in which we have made our own
function to copy string.
C program to copy a string
#include <stdio.h>
#include <string.h>
int main()
{
char source[1000], destination[1000];
printf("Input a string\n");
gets(source);
strcpy(destination, source);
printf("Source string: \"%s\"\n", source);
printf("Destination string: \"%s\"\n", destination);
return 0;
}
Output of program:
C program to copy string without using strcpy
We create our own function to copy string and do not use the
library function strcpy.
#include <stdio.h>
#include <string.h>
void copy_string(char [], char []);
int main() {
char s[1000], d[1000];
printf("Input a string\n");
gets(s);
copy_string(d, s);
printf("Source string: \"%s\"\n", s);
printf("Destination string: \"%s\"\n", d);
return 0;
}
void copy_string(char d[], char s[]) {
int c = 0;
while (s[c] != '\0') {
d[c] = s[c];
c++;
}
d[c] = '\0';
}
C
program to concatenate strings
This program concatenates strings, for example if the first
string is "c " and second string is "program" then on
concatenating these two strings we get the string "c program". To
concatenate two strings we use strcat function of string.h, to concatenate
without using library function see another code below which uses pointers.
C programming code
#include <stdio.h>
#include <string.h>
int main()
{
char a[1000], b[1000];
printf("Enter the first string\n");
gets(a);
printf("Enter the second string\n");
gets(b);
strcat(a,b);
printf("String obtained on concatenation is %s\n",a);
return 0;
}
Output of program:
Concatenate strings without strcat function
C program to concatenate strings without using library function
strcat of string.h header file. We create our own function.
#include <stdio.h>
void concatenate(char [], char []);
int main()
{
char p[100], q[100];
printf("Input a string\n");
gets(p);
printf("Input a string to concatenate\n");
gets(q);
concatenate(p, q);
printf("String obtained on concatenation is \"%s\"\n", p);
return 0;
}
void concatenate(char p[], char q[]) {
int c, d;
c = 0;
while (p[c] != '\0') {
c++;
}
d = 0;
while (q[d] != '\0') {
p[c] = q[d];
d++;
c++;
}
p[c] = '\0';
}
Reverse
string
This program reverses a string entered by the user. For example
if a user enters a string "reverse me" then on reversing the string
will be "em esrever". We show you four different methods to reverse
string the first one uses strrev library function of string.h header file, second without
using strrev and in
third we make our own function to reverse
string using pointers, reverse
string using recursion and Reverse words in string. If you are using first method
then you must include string.h in your program.
C programming code
/* String reverse in c*/
#include <stdio.h>
#include <string.h>
int main()
{
char arr[100];
printf("Enter a string to reverse\n");
gets(arr);
strrev(arr);
printf("Reverse of entered string is \n%s\n",arr);
return 0;
}
Output of program:
C program to reverse string without using function
Below code does not uses strrev library function to reverse a
string. First we calculate the length of string using strlen function and then
assigns characters of input string in reverse order to create a new string using
a for loop. You can also calculate length of string without using strlen. We
use comma operator in for loop to initialize multiple variables and
increment/decrement variables.
#include <stdio.h>
#include <string.h>
int main()
{
char s[100], r[100];
int n, c, d;
printf("Input a string\n");
gets(s);
n = strlen(s);
for (c = n - 1, d = 0; c >= 0; c--, d++)
r[d] = s[c];
r[d] = '\0';
printf("%s\n", r);
return 0;
}
C program for palindrome
#include <stdio.h>
#include <string.h>
int main()
{
char a[100], b[100];
printf("Enter the string to check if it is a palindrome\n");
gets(a);
strcpy(b,a);
strrev(b);
if (strcmp(a,b) == 0)
printf("Entered string is a palindrome.\n");
else
printf("Entered string is not a palindrome.\n");
return 0;
}
Output of program:
Palindrome number in c
#include <stdio.h>
main()
{
int n, reverse = 0, temp;
printf("Enter a number to check if it is a palindrome or not\n");
scanf("%d",&n);
temp = n;
while (temp != 0)
{
reverse = reverse * 10;
reverse = reverse + temp%10;
temp = temp/10;
}
if (n == reverse)
printf("%d is a palindrome number.\n", n);
else
printf("%d is not a palindrome number.\n", n);
return 0;
}
C program for palindrome without using string functions
#include <stdio.h>
#include <string.h>
int main()
{
char text[100];
int begin, middle, end, length = 0;
gets(text);
while (text[length] != '\0')
length++;
end = length - 1;
middle = length/2;
for (begin = 0; begin < middle; begin++)
{
if (text[begin] != text[end])
{
printf("Not a palindrome.\n");
break;
}
end--;
}
if (begin == middle)
printf("Palindrome.\n");
return 0;
}
C
program remove spaces, blanks from a string
C code to remove spaces or excess blanks from a string, For
example consider the string
"c programming"
There are two spaces in this string, so our program will print a
string
"c programming". It will remove spaces when they occur more than one time consecutively in string anywhere.
"c programming". It will remove spaces when they occur more than one time consecutively in string anywhere.
C programming code
#include <stdio.h>
int main()
{
char text[1000], blank[1000];
int c = 0, d = 0;
printf("Enter some text\n");
gets(text);
while (text[c] != '\0') {
if (text[c] == ' ') {
int temp = c + 1;
if (text[temp] != '\0') {
while (text[temp] == ' ' && text[temp] != '\0') {
if (text[temp] == ' ') {
c++;
}
temp++;
}
}
}
blank[d] = text[c];
c++;
d++;
}
blank[d] = '\0';
printf("Text after removing blanks\n%s\n", blank);
return 0;
}
C
program to find frequency of characters in a string
This program computes frequency of characters in a string i.e.
which character is present how many times in a string. For example in the
string "code" each of the character 'c', 'o', 'd', and 'e' has
occurred one time. Only lower case alphabets are considered, other characters
(uppercase and special characters) are ignored. You can easily modify this
program to handle uppercase and special symbols.
C programming code
#include <stdio.h>
#include <string.h>
int main()
{
char string[100];
int c = 0, count[26] = {0};
printf("Enter a string\n");
gets(string);
while (string[c] != '\0')
{
/** Considering characters from 'a' to 'z' only
and ignoring others */
if (string[c] >= 'a' && string[c] <= 'z')
count[string[c]-'a']++;
c++;
}
for (c = 0; c < 26; c++)
{
/** Printing only those characters
whose count is at least 1 */
if (count[c] != 0)
printf("%c occurs %d times in the entered string.\n",c+'a',count[c]);
}
return 0;
}
C program to open a file and read
C programming code to open a file and to print it contents on
screen.
#include <stdio.h>
#include <stdlib.h>
int main()
{
char ch, file_name[25];
FILE *fp;
printf("Enter the name of file you wish to see\n");
gets(file_name);
fp = fopen(file_name,"r"); // read mode
if( fp == NULL )
{
perror("Error while opening the file.\n");
exit(EXIT_FAILURE);
}
printf("The contents of %s file are :\n", file_name);
while( ( ch = fgetc(fp) ) != EOF )
printf("%c",ch);
fclose(fp);
return 0;
}
C
program to copy files
C program to copy files: This program copies a file, firstly you
will specify the file to copy and then you will enter the name of target file,
You will have to mention the extension of file also. We will open the file that
we wish to copy in read mode and target file in write mode.
C programming code
#include <stdio.h>
#include <stdlib.h>
int main()
{
char ch, source_file[20], target_file[20];
FILE *source, *target;
printf("Enter name of file to copy\n");
gets(source_file);
source = fopen(source_file, "r");
if( source == NULL )
{
printf("Press any key to exit...\n");
exit(EXIT_FAILURE);
}
printf("Enter name of target file\n");
gets(target_file);
target = fopen(target_file, "w");
if( target == NULL )
{
fclose(source);
printf("Press any key to exit...\n");
exit(EXIT_FAILURE);
}
while( ( ch = fgetc(source) ) != EOF )
fputc(ch, target);
printf("File copied successfully.\n");
fclose(source);
fclose(target);
return 0;
}
C
program to merge two files
This c program merges two files and stores their contents in
another file. The files which are to be merged are opened in read mode and the
file which contains content of both the files is opened in write mode. To merge
two files first we open a file and read it character by character and store the
read contents in another file then we read the contents of another file and
store it in file, we read two files until EOF (end of file) is reached.
C programming code
#include <stdio.h>
#include <stdlib.h>
int main()
{
FILE *fs1, *fs2, *ft;
char ch, file1[20], file2[20], file3[20];
printf("Enter name of first file\n");
gets(file1);
printf("Enter name of second file\n");
gets(file2);
printf("Enter name of file which will store contents of two files\n");
gets(file3);
fs1 = fopen(file1,"r");
fs2 = fopen(file2,"r");
if( fs1 == NULL || fs2 == NULL )
{
perror("Error ");
printf("Press any key to exit...\n");
getch();
exit(EXIT_FAILURE);
}
ft = fopen(file3,"w");
if( ft == NULL )
{
perror("Error ");
printf("Press any key to exit...\n");
exit(EXIT_FAILURE);
}
while( ( ch = fgetc(fs1) ) != EOF )
fputc(ch,ft);
while( ( ch = fgetc(fs2) ) != EOF )
fputc(ch,ft);
printf("Two files were merged into %s file successfully.\n",file3);
fclose(fs1);
fclose(fs2);
fclose(ft);
return 0;
}
C
program to delete a file
This c program deletes a file which is entered by the user, the
file to be deleted should be present in the directory in which the executable
file of this program is present. Extension of the file should also be entered,
remove macro is used to delete the file. If there is an error in deleting the
file then an error will be displayed using perror function.
C programming code
#include<stdio.h>
main()
{
int status;
char file_name[25];
printf("Enter the name of file you wish to delete\n");
gets(file_name);
status = remove(file_name);
if( status == 0 )
printf("%s file deleted successfully.\n",file_name);
else
{
printf("Unable to delete the file\n");
perror("Error");
}
return 0;
}
Example of structure
#include <stdio.h>
struct Distance
{
int feet;
float inch;
} dist1, dist2, sum;
int main()
{
printf("1st distance\n");
// Input of feet for structure variable dist1
printf("Enter feet: ");
scanf("%d", &dist1.feet);
// Input of inch for structure variable dist1
printf("Enter inch: ");
scanf("%f", &dist1.inch);
printf("2nd distance\n");
// Input of feet for structure variable dist2
printf("Enter feet: ");
scanf("%d", &dist2.feet);
// Input of feet for structure variable dist2
printf("Enter inch: ");
scanf("%f", &dist2.inch);
sum.feet = dist1.feet + dist2.feet;
sum.inch = dist1.inch + dist2.inch;
if (sum.inch > 12)
{
//If inch is greater than 12, changing it to feet.
++sum.feet;
sum.inch = sum.inch - 12;
}
// printing sum of distance dist1 and dist2
printf("Sum of distances = %d\'-%.1f\"", sum.feet, sum.inch);
return 0;
}
Referencing pointer to another
address to access the memory
Consider an example to access structure's member through
pointer.
#include <stdio.h>
typedef struct person
{
int age;
float weight;
};
int main()
{
struct person *personPtr, person1;
personPtr = &person1; // Referencing pointer to memory address of person1
printf("Enter integer: ");
scanf("%d",&(*personPtr).age);
printf("Enter number: ");
scanf("%f",&(*personPtr).weight);
printf("Displaying: ");
printf("%d%f",(*personPtr).age,(*personPtr).weight);
return 0;
}
Example of Pointer And
Functions ( call by reference)
Program to swap two
number using call by reference.
/* C Program to swap two numbers using pointers and function. */
#include <stdio.h>
void swap(int *n1, int *n2);
int main()
{
int num1 = 5, num2 = 10;
// address of num1 and num2 is passed to the swap function
swap( &num1, &num2);
printf("Number1 = %d\n", num1);
printf("Number2 = %d", num2);
return 0;
}
void swap(int * n1, int * n2)
{
// pointer n1 and n2 points to the address of num1 and num2 respectively
int temp;
temp = *n1;
*n1 = *n2;
*n2 = temp;
}
Self-referential structures
typedef struct NODE {
struct NODE *new;
int value;
}Node;
int main(void)
{
Node previous, current;
/* accessing members of 'previous' */
previous.new = ¤t;
/* previous.new is a 'pointer-to-struct NODE' */
previous.value = 100;
}
In
above fragment of code, ‘previous.new’ is pointing to ‘current’ Node.
Self-referential structures have their applications in Advanced Data Structures like, Linked Lists, Binary Trees etc..
Self-referential structures have their applications in Advanced Data Structures like, Linked Lists, Binary Trees etc..
Difference between union and structure
Though unions are similar to structure in so many ways, the
difference between them is crucial to understand.
The primary difference can be demonstrated by this example:
#include <stdio.h>
union unionJob
{
//defining a union
char name[32];
float salary;
int workerNo;
} uJob;
struct structJob
{
char name[32];
float salary;
int workerNo;
} sJob;
int main()
{
printf("size of union = %d", sizeof(uJob));
printf("\nsize of structure = %d", sizeof(sJob));
return 0;
}
R16
Programming Questions
Write program
for printing identity matrix on screen.
Write a program
to print the following series on the screen
1
1 2
1 2 3
1 2 3 4
1 2 3 4 5
Write a c
program to generate perfect numbers from1 to n, where n is supplied by the
user.
Write a c
program to find biggest number among 3 numbers
Write a c
program to generate Fibonacci series
numbers below 1000.
Write a
program to declare pointer to a structure and display the contents of the structure Define a structure object
book with three fields : title ,author and pages.
Write a c
program to read two complex numbers and perform add and subtraction.
Write a c
program to replace every 5th character of the data file.
Write a
program to find the prime numbers in given range.
R13
Programming Questions
Write a
recursive function for finding the factorial value of a given number.
How pointers
can be used for declaring of multi dimensional arrays? Discuss.
Write a
program to multiply two matrices using pointer.
Write a
program to print file contents in reverse order.
Write a
program to find the sum of the series: 1+22+32+……
Write a C
program to calculate the total of the series: 1+(1/22)+(1/32)+…..
Write a
program to find the 43^2 value.
Write a
program to print the following matrix on the screen.
a b c d
e
f g
h i j
k l m n
o
p q r s t
Write a C
program that defines a structure student with members name, average, address
and displays
the category of student according to the following criteria
average>=70------Distinction
60<=average<70-------First
Class
50<=average<60-------Second
Class
40<=average<50--------Third
Class
average<40--------Fail
