题解 | #实现简单计算器功能#

#include <iostream>
#include <string>
using namespace std;

int main() {

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

    // 遍历字符串，根据空格数目，进行op，整数1，整数2的划分
    int spacenum = 0;
    string op = "";
    string num_1 = "";
    string num_2 = "";
    for (int i = 0; str[i] != '\0'; i++){
        if (str[i] == ' '){
            spacenum++;
            continue;    
        }
        else if (spacenum == 0){
            str[i] = tolower(str[i]);
            op += str[i];   //op为数组
        }
            
        else if (spacenum == 1)
            num_1 += str[i];
        else if (spacenum == 2)
            num_2 += str[i];
            
    }
    //字符串类型转化为整型
    int x = stoi(num_1);
    int y = stoi(num_2);
    if ((string)op == "add")  //数组类型转化为字符串类型
        cout << x + y;
    else if ((string)op == "sub")
        cout << x - y;
    else if ((string)op == "mul")
        cout << x*y;
    else if ((string)op == "div"){
            if (y != 0)
            cout << x/y;
            else cout << "Error";
    }


    return 0;
}