#include <iostream> #include <cstring> using namespace std; int main() { // 洞1~10，vis[0]不用 bool vis[11]; memset(vis, false, sizeof(vis)); // 循环1到1000次查找 for (int k = 1; k <= 1000; ++k) { long long sum = (long long)k * (k + 1) / 2; int pos = sum % 10; if (pos == 0) pos = 10; vis[pos] = true; } cout << "狐狸1000次都没找到兔子，兔子藏身的洞号：" << endl; for (int i = 1; i <= 10; ++i) { if (!vis[i]) { cout << i << " "; } } cout << endl; return 0; }