循环-04. 验证“哥德巴赫猜想”(20)

#include<iostream>
#include<cmath>
using namespace std;
bool isPrime(long n){
int i;
for(i=2;i<=sqrt(n);++i)
if(n%i==0)
break;
if(n>1&&i>sqrt(n))
return true;
else
return false;
}
int main(){
long i,n;
cin>>n;
for(i=2;i<=n/2;++i)
if(isPrime(i)&&isPrime(n-i)){
cout<<n<<" = "<<i<<" + "<<n-i<<endl;
break;
}
return 0;
}