哥德巴赫猜想题解

#include <bits/stdc++.h>
using namespace std;
bool a[10086];
int n;
int main(){
    cin >> n;
    for(int i = 2;i <= n;i ++){
        if(a[i] == 0){
            for(int j = i + i;j <= n;j += i) a[j] = 1;
        }
    }
    for(int i = 4;i <= n;i += 2){
        for(int j = 2;j <= i;j ++){
            if(a[j] == 0 && a[i - j] == 0){
                cout << i << '=' << j << '+' << i-j << endl;
                break;
            }
        }
    }
    return 0;
}