辅助判卷程序项目的扩展--自动出题

#include <iostream>
using namespace std;
#include <string>
#include <fstream>
#include<time.h>
#include<stdlib.h>

#define random(x) (rand()%x)

bool isoperator(char c){
    if(c==‘+‘||c==‘-‘||c==‘*‘||c==‘/‘)
        return true;
    return false;
}

int main(int argc, char** argv) {
    srand((int)time(0));
    string equation;
    char temp[100];
    ofstream outf("equation.txt");
    int i=0;
    cout<<"输入生成算式的数量：";
    cin>>i;
    while(i--){
        equation.clear();
        if(i%2){                                            //分数运算 
            char lastop=‘+‘;                                //上一个运算符 
            int num=random(7)+4;                            //算式包含的操作数个数-1 
            sprintf(temp,"%d",random(20)+1);                 //第一个操作数 
            equation.append(temp);
            while(num--){
                int b;                        
                if(lastop==‘/‘)                            //防止连续除法的出现 
                    b=random(2);
                else
                    b=random(12);
                switch(b){
                case 0:
                case 4:
                case 8:
                    lastop=temp[0]=‘+‘;
                    break;
                case 1:
                case 5:
                case 9:
                    lastop=temp[0]=‘-‘;
                    break;
                case 2:
                case 6:
                case 10:
                    lastop=temp[0]=‘*‘;
                    break;
                case 3:
                case 7:
                case 11:
                    lastop=temp[0]=‘/‘;
                    break;
                } 
                temp[1]=0;
                equation.append(temp);
                sprintf(temp,"%d",random(20)+1);                 
                equation.append(temp);
            }
            int k,a=0;
            for(int j=0;j<equation.size();j++){                    //添加括号 
                if((equation[j]==‘+‘||equation[j]==‘-‘)&&a==0){
                    a++;
                } 
                else if((equation[j]==‘+‘||equation[j]==‘-‘)&&a==1){
                    k=j-1;                                            //添加左括号 
                    while(!isoperator(equation[k-1])&&k!=0) k--;
                    if(equation[k-1]==‘/‘){
                        k--;
                        while(!isoperator(equation[k-1])&&k!=0) k--;
                    }
                    equation.insert(k,"(");
                    
                    k=j+2;                                            //添加右括号 
                    while(!isoperator(equation[k+1])&&k!=equation.size()-1) k++;
                    equation.insert(k+1,")");
                    
                    break;
                }
            }
            //cout<<equation<<endl;
        }
        else{                                                        //小数运算 
            char lastop=‘+‘;                                //上一个运算符 
            int num=random(7)+4;                            //算式包含的操作数个数-1 
            int temp1=random(200)+1;
            sprintf(temp,"%g",temp1/10.0);                 //第一个操作数 
            equation.append(temp);
            while(num--){
                int b;                        
                if(lastop==‘/‘)                            //防止连续除法的出现 
                    b=random(2);
                else
                    b=random(12);
                switch(b){
                case 0:
                case 4:
                case 8:
                    lastop=temp[0]=‘+‘;
                    break;
                case 1:
                case 5:
                case 9:
                    lastop=temp[0]=‘-‘;
                    break;
                case 2:
                case 6:
                case 10:
                    lastop=temp[0]=‘*‘;
                    break;
                case 3:
                case 7:
                case 11:
                    lastop=temp[0]=‘/‘;
                    break;
                } 
                temp[1]=0;
                equation.append(temp);
                int temp2=random(200)+1;
                if(equation[equation.size()-1]==‘/‘&&(temp1%temp2)!=0){
                    temp2=temp1/5+1;
                    while(temp1%temp2){
                        temp2++;
                    }
                }
                temp1=temp2;
                sprintf(temp,"%g",temp2/10.0);                
                equation.append(temp);
            }
            //cout<<equation<<endl;
        }
        outf<<equation<<endl; 
    }
    cout<<"生成算式成功"<<endl; 
    outf.close();
    return 0;
}