write a C Program to check if the user given input number is a Prime Number or not

Filed in C Program Examples 0 comments

A prime number (or a prime) is a natural number that has exactly two distinct natural number divisors 1 and itself.
3, 5, 7, 9, 13 are prime nubmers

forexample:
number 3 has only divisors of 1 and 3
5 is also dividable with only with 2 numbers 1 and 5

So lets get started creating a program to check if the input number is prime or not

#include <stdio.h>
#include <conio.h>
void main(){
int input_num;
int i;
int counter=0;
int divisors = 0;

scanf("%d",&input_num);

for(i=2;i<=input_num;i++)
{
if(!(input_num % i))
{
divisors++;
}
}
if(divisors==1)
{
printf("THis number has only one %d divisors so that \n",divisors);
printf("%d is a prime number",input_num);
}else{
printf("%d is not a prime number",input_num);
}
getch();
}

Posted by voshka @ 25 March 2011 0 comments