[C++]素数判定

#include<iostream>
using namespace std;
int main(){
	cout<<"please input a number: \n";
	int m; //先定义后使用 
	cin>>m;
	for (int i=2;i<=m-1;i++){
		if (m%i==0){
			cout<<m<<" isn't a prime. \n'";
			return 1; 
		}
	}
	cout<<m<<" is a prime. \n";
}