FractionCalculation.java

package com.four.user;

import java.util.Scanner;
import java.math.*;

public class FractionCalculation {
    public char operate(){
        int i;
        char op = ' ';
        i=(int)(Math.random()*100)%4+1;
        switch(i){
            case 1:op='+';break;
            case 2:op='-';break;
            case 3:op='*';break;
            case 4:op='/';
        }
        return op;
    }

    public int num(){
        int i;
        i=(int)(Math.random()*100);
        return i;
    }

    public void intmatch(){//整数出题
        int a=this.num();
        int b=this.num();
        char op=this.operate();
        //int answer;
        String myanswer;
        System.out.print("请做题："+a+op+b+"=");
        String answer1=this.intcalculate(a, op, b);
        //System.out.print(answer1);
        Scanner in= new Scanner(System.in);
        myanswer=in.next();
        if(myanswer.equals(answer1)){
            System.out.println("恭喜，答案正确。");
        }
        else{
            System.out.println("很抱歉，答案错误。正确答案为："+answer1);
        }
    }

    public String intcalculate(int a,char op,int b){//整数之间的计算方法
        if(op=='+')
            return (a+b)+"";
        else if(op=='-')
            return (a-b)+"";
        else if(op=='*')
            return (a*b)+"";
        else{
            int max=this.maxyueshu(a, b);
            a=a/max;
            b=b/max;
            if(b==1){
                return a+"";
            }
            else{
                Fraction t=new Fraction(a,b);
                String tt=t.toString();
                return tt;
            }
        }
    }



    public int maxyueshu( int a, int b ){
        return a%b==0?b:maxyueshu(b,a%b);
    }

    public Fraction simple(Fraction a){
        int max=this.maxyueshu(a.denominator, a.numerator);
        a.denominator=a.denominator/max;
        a.numerator=a.numerator/max;
        return a;
    }


    public Fraction fraccalculate(Fraction a,char op,Fraction b){//分数之间的计算
        int fenzi,fenmu;

        if(op=='+'){
            fenzi=a.denominator*b.numerator+a.numerator*b.denominator;
            fenmu=a.denominator*b.denominator;
        }else if(op=='-'){
            fenzi=a.numerator*b.denominator-a.denominator*b.numerator;
            fenmu=a.denominator*b.denominator;
        }else if(op=='*'){
            fenzi=a.numerator*b.numerator;
            fenmu=a.denominator*b.denominator;
        }else{
            fenzi=a.numerator*b.denominator;
            fenmu=a.denominator*b.numerator;
        }
        if(fenzi*fenmu==0){
            return new Fraction(fenzi, fenmu);
        }else{
            return this.simple(new Fraction(fenzi,fenmu));
        }

    }


    public void frcmatch(){//分数形式b1/a1和b2/a2
        int a1=0,b1=0,a2=0,b2=0;
        char op=' ';
        String myanswer;
        while(b1>=a1){
            a1=this.num()+1;
            b1=this.num();
        }
        Fraction t1=this.simple(new Fraction(a1,b1));
        while(b2>=a2){
            a2=this.num()+1;
            b2=this.num();
        }
        Fraction t2=this.simple(new Fraction(a2,b2));
        op=this.operate();
        if(op=='/'&&t2.numerator==0){//判读第二个分数的分子是否等于0，此时的分数不能执行除法
            this.frcmatch();
        }else{
            System.out.print("请做题：("+t1.toString()+")"+op+"("+t2.toString()+")=");
        }
        Fraction answer=new Fraction(1,1);
        answer=this.fraccalculate(t1, op, t2);
        Scanner in= new Scanner(System.in);
        myanswer=in.next();
        if(myanswer.equals(answer.toString())){
            System.out.println("恭喜，答案正确。");
        }
        else{
            System.out.println("很抱歉，答案错误。正确答案为："+answer);
        }
    }

//    public static void main(String[] args) {
//        FractionCalculation a=new FractionCalculation();
//        int num;
//        for(num=1;num<=100;num++){
//            int i=a.num();
//            if(i>50)
//                a.intmatch();
//            else
//                a.frcmatch();
//        }
//    }

}