#include <iostream> #include <cstdio> #include <algorithm> #include <string> using namespace std; int a, b; char s; //复习一下getline()函数 getline(cin, 字符串变量) int main() { //重点是阶乘的输入怎么处理 while (cin >> a >> s) { if (s == '!') { if (a == 0) { cout << 1 << endl; break; } else { int res = 1; for (int i = 1; i <= a; i++) { res *= i; } cout << res << endl; } } else { cin >> b; if (s == '+') cout << a + b << endl; else if (s == '-') cout << a - b << endl; else if (s == '*') cout << a * b << endl; else if (s == '/') { if (b == 0) { cout << "error" << endl; break; } else { cout << a / b << endl; } } else { if (b == 0) { cout << "error" << endl; break; } else { cout << a % b << endl; } } } } return 0; }