//李俏，2016.3.7
//随机生成四则运算

#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<time.h>
using namespace std;int main()
{int first,second,firstm,secondm;int sign,i,j;int num,chengchu,fushu,yushu,fanwei;cout<<"请输入题目数量：";cin>>num;if(num==0){exit(1);}cout<<"是否有乘除法？1.是，2.否：";cin>>chengchu;if(chengchu==1){cout<<"除法是否有余数？1.是，2.否：";cin>>yushu;}cout<<"减法是否有负数？1.是，2.否：";cin>>fushu;cout<<"请输入数值范围：";cin>>fanwei;srand((int)time(NULL)); //用时间做种子，每次产生随机数都不一样for(i=0;i<num;i++){j=rand()%2;        //选择生成整数运算还是分数运算if(j==0)           //选择整数
        {first=rand()%(fanwei+1);second=rand()%(fanwei+1);if(chengchu==1){sign=rand()%4; }else{sign=rand()%2;}switch(sign){case 0:                      //整数加法cout<<first<<"+"<<second<<"="<<endl;break;case 1:                      //整数减法if(fushu==1){cout<<first<<"-"<<second<<"="<<endl;}else{if(first>second){cout<<first<<"-"<<second<<"="<<endl;}else{cout<<second<<"-"<<first<<"="<<endl;}}break;case 2:                   //整数乘法cout<<first<<"*"<<second<<"="<<endl;break; case 3:                   //整数除法if(yushu==1){if(second!=0){cout<<first<<"/"<<second<<"="<<endl;}else{i=i-1;}}else{if(second!=0&&(first%second==0)){cout<<first<<"/"<<second<<"="<<endl;}else{i=i-1;}}break;}}else              //选择分数
        {first=rand()%(fanwei+1);                        second=rand()%(fanwei+1);//分子firstm=rand()%(fanwei+1);secondm=rand()%(fanwei+1);//分母if(chengchu==1){sign=rand()%4;}else{sign=rand()%2;}switch(sign){case 0:                //分数加法if(firstm!=0&&secondm!=0&&first<firstm&&second<secondm){cout<<first<<"/"<<firstm<<"  +  "<<second<<"/"<<secondm<<"="<<endl;}else{i=i-1;}break;case 1:                //分数减法if(fushu==1){if(firstm!=0&&secondm!=0&&first<firstm&&second<secondm){cout<<first<<"/"<<firstm<<"  -  "<<second<<"/"<<secondm<<"="<<endl;}else{i=i-1;}}else{if(firstm!=0&&secondm!=0&&first<firstm&&second<secondm&&(first/firstm)>(second/secondm)){cout<<first<<"/"<<firstm<<"  -  "<<second<<"/"<<secondm<<"="<<endl;}else{i=i-1;}}break;case 2:                //分数乘法if(firstm!=0&&secondm!=0&&first<firstm&&second<secondm){cout<<first<<"/"<<firstm<<"  *  "<<second<<"/"<<secondm<<"="<<endl;}else{i=i-1;}break;case 3:                //分数除法if(firstm!=0&&secondm!=0&&first!=0&&second!=0&&first<firstm&&second<secondm){cout<<first<<"/"<<firstm<<"  /  "<<second<<"/"<<secondm<<"="<<endl;}else{i=i-1;}break;}}}

    return 0;
}