C Programming Code Examples
C > Recursion Code Examples
C Program to Find whether a Number is Prime or Not using Recursion
/* C Program to Find whether a Number is Prime or Not using Recursion
The following C program, using recursion, finds whether the entered number is a prime number or not. A prime number is an integer that has no integral factor but itself and 1. */
#include <stdio.h>
int primeno(int, int);
int main()
{
int j, check;
printf("Enter a number: ");
scanf("%d", &j);
check = primeno(j, j / 2);
if (check == 1)
{
printf("%d is a prime number\n", j);
}
else
{
printf("%d is not a prime number\n", j);
}
return 0;
}
int primeno(int j, int x)
{
if (x == 1)
{
return 1;
}
else
{
if (j % x == 0)
{
return 0;
}
else
{
return primeno(j, x - 1);
}
}
}
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