题解 | #实现简单计算器功能#

#include <iostream>
#include <sstream>
#include <algorithm>
using namespace std;

int main() {

    char str[100] = { 0 };
    cin.getline(str, sizeof(str));

    // write your code here......
    string s {str};  // char 字符串 转换为 string
    istringstream is {s};  // 将一个string对象作为istream的源

    string op;
    int n1, n2;

    is >> op >> n1 >> n2;

    transform(op.begin(), op.end(), op.begin(), ::tolower);

    if (op == "add") {
        cout << n1+n2;
    } else if (op == "sub") {
        cout << n1-n2;
    } else if (op == "mul") {
        cout << n1*n2;
    } else if (op == "div") {
        if (n2 == 0)
            cout << "Error";
        else
            cout << n1/n2;
    }

    return 0;
}