f0208.cpp 判断一个数是否是素数

//======================
//f0208.cpp
//判断一个数是否是素数
//=====================
#include<iostream>
#include<cmath>
using namespace std;
//---------------------
bool isPrime(int m);
//---------------------
bool isPrime(int m)
{
double sqrtm = sqrt(m * 1.0);
for(int i = 2;i <= sqrtm;i++)
if(m % i == 0)
return 0;
return 1;
}
int main()
{
cout << "plsease input a number:"<<endl;
int m;
cin >> m;
if(isPrime(m))
cout << m << " is a prime." <<endl;
else
cout << m << " is not a prime." <<endl;
return 0;
}