#include<iostream>
#include<cstdlib>
#include<math.h>
#include<stdio.h>
#include<ctime>
 using namespace std;

int r=0;
int w=0;

void add() { //加法运算
	srand(time(0));
    int a,b,c,d; 
    a=rand()%100;
    b=rand()%100;
    c=rand()%100;
    cout<<"请回答："<<a<< "+"<<b<< "+"<<c<< "= ";
    cin>>d;
    if(a+b+c==d) {
        cout<<"回答正确!";
        r++;
    } else {
        cout<<"回答错误!";
        w++;
    }
}

void minus() { //减法运算
	srand(time(0));
    int a,b,c,d;
    a=rand()%100;
    b=rand()%100;
    c=rand()%100;
     cout<<"请回答："<<a<< "-"<<b<< "-"<<c<< "= ";
    cin>>d;
    if(a-b-c==d) {
        cout<<"回答正确!";
        r++;
    } else {
        cout<<"回答错误!";
        w++;
    }
}

void multiply() { //乘法运算
	srand(time(0));
    int a,b,c,d;
    a=rand()%100;
    b=rand()%100;
    c=rand()%100;
     cout<<"请回答："<<a<< "*"<<b<< "*"<<c<< "= ";
    cin>>d;
    if(a*b*c==d) {
        cout<<"回答正确!";
        r++;
    } else {
        cout<<"回答错误!";
        w++;
    }
}

void divide() { //除法运算
	srand(time(0));
    int a,b,c,d;
    a=rand()%100;
    b=rand()%100;
    c=rand()%100;
     cout<<"请回答："<<a<< "/"<<b<< "/"<<c<< "= ";
    cin>>d;
    if(a/b/c==d) {
       cout<<"回答正确!";
        r++;
    } else {
        cout<<"回答错误!";
        w++;
    }
}

void main() {
    int choise;
    int con=0;
    int i=0,j=0;
    cout<<"欢迎进入简易四则运算";
    while(1) {
        cout<<"请选择：";
        cout<<"  加法运算（请输入1）";
        cout<<"  减法运算（请输入2）";
        cout<<"  乘法运算（请输入3）";
       cout<<"  除法运算（请输入4）";
        cout<<"  退出运算（请输入5）";
        if(con==0)
            cin>>choise;
        switch(choise) {
            
            case 1://加法
                cout<<"请输入题目数目：";
                cin>>i;
                if(i>0) {
                    for(j=0; j<i; j++) {
                        add();
                    }
                } else
                    cout<<"输入错误，请重新输入！";
                break;

            case 2://减法
                cout<<"请输入题目数目：";
                cin>>i;
                if(i>0) {
                    for(j=0; j<i; j++) {
                        minus();
                    }
                } else
                    cout<<"输入错误，请重新输入！";
                break;

            case 3://乘法
                cout<<"请输入题目数目：";
                cin>>i;
                if(i>0) {
                    for(j=0; j<i; j++) {
                        multiply();
                    }
                } else
                   cout<<"输入错误，请重新输入！";
                break;

            case 4://除法
                cout<<"请输入题目数目：";
                cin>>i;
                if(i>0) {
                    for(j=0; j<i; j++) {
                        divide();
                    }
                } else
                    printf("输入错误，请重新输入！");
                break;
            case 5:
                return;
        }
        cout<<"继续运算？（请输入1）";
       cout<<"重新选择？";
        cout<<"退出运算？（请输入3）";
        cin>>con;
        if(con==1)
            con=1;
        else if(con==2)
            con=0;
        else if(con==3)
            break;
        else
            cout<<"抱歉!，你输入的指令有误!请重新输入!";
    }
    cout<<"您总共完成了"<<r+w<<"道题  正确"<<r<<"道  错误"<<w<<"道";

  system("pause");
 
}