prime numbers check in cpp code example
Example 1: check prime in c++
#include <bits/stdc++.h>
#include <math.h>
using namespace std;
#define ll long long
bool checkPrime(int number){
for(int i=2; i<=sqrt(number); i++){
if(number%i==0){
return false;
}
}
return true;
}
Example 2: check prime number c++
#include <iostream>
using namespace std;
int main() {
int i, n;
bool isPrime = true;
cout << "Enter a positive integer: ";
cin >> n;
if (n == 0 || n == 1) {
isPrime = false;
}
else {
for (i = 2; i <= n / 2; ++i) {
if (n % i == 0) {
isPrime = false;
break;
}
}
}
if (isPrime)
cout << n << " is a prime number";
else
cout << n << " is not a prime number";
return 0;
}
Example 3: C++ prime number check
bool is_prime6(int num) {
int i;
if (num == 1)
return false;
if (num <= 3)
return true;
if (num % 2 == 0 || num % 3 == 0)
return false;
if (num < 25)
return true;
for (i = 5; i * i <= num; i += 6)
if (num % i == 0 || num % (i + 2) == 0)
return false;
return true;
}