Answers for "You are given one number N. You must write a program to test whether the given number is prime or not. NOTE : A prime number is such a number that has only two factors : i.e. 1 and itself. 1 is not a prime number."

program to know if a number is prime

#include<bits/stdc++.h>
using namespace std;
bool Is_Prime(long long x){
	if(x%2==0)return false;
	for(int i=3;i*i<=x;i+=2)
		if(x%i==0)return false;
	return true;
}
int main(){
	long long x;
	cin>>x;
	if(Is_Prime(x))cout<<"Is Prime";
	else cout<<"Is not Prime";
}