#include <iostream> using namespace std; int main() { int a, b; char op; // 按照 "a op b" 的格式读取 cin >> a >> op >> b; long long result; // 使用long long防止溢出 switch(op) { case '+': result = (long long)a + b; break; case '-': result = (long long)a - b; break; case '*': result = (long long)a * b; break; case '/': result = (long long)a / b; // 整数除法 break; default: return 1; // 不应该发生 } cout << result << endl; return 0; }