C Exercises: Check whether a given number is prime or not

C For Loop: Exercise-32 with Solution

Write a C program to determine whether a given number is prime or not.

Pictorial Presentation:

Sample Solution:

C Code:

#include <stdio.h>

void main(){

    int num,i,ctr=0;
    printf("Input  a number: ");
    scanf("%d",&num);
    for(i=2;i<=num/2;i++){
        if(num % i==0){
         ctr++;
            break;
        }
    }
   if(ctr==0 && num!= 1)
        printf("%d is a prime number.\n",num);
   else
      printf("%d is not a prime number",num);
}

Sample Output:

Input  a number: 13                                                                                           
13 is a prime number. 

Flowchart:

C Programming Code Editor:

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