A175.Gold King假想

我们只需要一个函数来判断素数，然后暴力

#include<bits/stdc++.h>
using namespace std;
bool p(int n){
	if(n<2) {
        return 0;
    }
	for(int i=2;i<=n/i;++i){
        if(n%i==0){
            return 0;   
        } 
    }	
	return 1;
}
int main(){
    int n;
    while(1){
        cin>>n;
        if(n==0) {
            break;
        }
        if(n<6||n%2==1){
              cout<<"Goldbach's conjecture is wrong."<<endl;  
        } 
    	else{
		for(int i=3;i<=n/2;i+=2)
			if((p(i))&&(p(n-i))){
				cout<<n<<" = "<<i<<" + "<<n-i<<endl;
				break;
			}
    	}
    }
    return 0;
}