cin cout보다 scanf printf가 더 빠르다
#include <algorithm>
#include <iostream>
#include <stdio.h>
#include <vector>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <string>
#include <cmath>
#include <time.h>
using namespace std;
int main() {
//freopen("input.txt", "rt", stdin);
bool arr[1000001];
for (int i = 2; i <= 1000000; i++) {
arr[i] = 1;
}
for (int i = 2; i <= sqrt(1000000); i++) {
for (int j = i * 2; j <= 1000000; j += i) {
if (arr[j] == 0) {
continue;
}
arr[j] = 0;
}
}
int num;
while (1) {
scanf("%d", &num);
if (num == 0) {
break;
}
int flag = 0;
for (int i = 3; i <= num / 2; i += 2) {
if (arr[i]==1 && arr[num - i] == 1) {
flag = 1;
printf("%d = %d + %d\n", num, i, num - i);
break;
}
}
if (flag == 0) {
printf("Goldbach's conjecture is wrong.\n");
}
}
return 0;
}