isprime c 2b 2b

1#include <iostream>
2using namespace std;
3
4int main()
5{
6  int n, i;
7  bool isPrime = true;
8
9  cout << "Enter a positive integer: ";
10  cin >> n;
11
12  for(i = 2; i <= n / 2; ++i)
13  {
14      if(n % i == 0)
15      {
16          isPrime = false;
17          break;
18      }
19  }
20  if (isPrime)
21      cout << "This is a prime number";
22  else
23      cout << "This is not a prime number";
24
25  return 0;
26}

1bool isprime(int n)
2{
3    if(n<=1)
4        return false;
5    for (int i = 2; i <= sqrt(n); i++)
6        if (n % i == 0)
7            return false;
8  
9    return true;
10}

1#include<bits/stdc++.h>
2using namespace std;
3bool Is_Prime(long long x){
4	if(x%2==0)return false;
5	for(int i=3;i*i<=x;i+=2)
6		if(x%i==0)return false;
7	return true;
8}
9int main(){
10	long long x;
11	cin>>x;
12	if(Is_Prime(x))cout<<"Is Prime";
13	else cout<<"Is not Prime";
14}