四则运算

一、程序设计思想

通过while限制条件，用随机数产生算式。通过if判断对错，通过循环中的n++计数。

二、源代码

import java.util.Random;
import java.util.Scanner;

public class Yun {
     
    public static void main(String[] args) {
        int x,z,y,n=0;
         for ( int i = 1; i <=60; i++ ) {
             Scanner in=new Scanner(System.in);
             z= 1 + (int) ( Math.random() * 100 );
             y=1 + (int) ( Math.random() * 100 );
             x=1 + (int) ( Math.random() * 3);
             while(z+y>100||z-y<0||z*y>100||(z/y)%1!=0) {
                 z= 1 + (int) ( Math.random() * 100 );
                 y=1 + (int) ( Math.random() * 100 );
                 x=new Random().nextInt(4)+1;
             }
             if(x==1) {
                 System.out.println(z+"加"+y+"=");
                 System.out.println("请输入结果");
                 int jia=in.nextInt();
                 if(jia==z+y) {
                     System.out.println("对");
                    n++; 
                 }
                     else {
                         System.out.println("错"); 
                     }
                 
                 }
             else if(x==2) {
                 System.out.println(z+"减"+y+"=");
                 System.out.println("请输入结果");
                 int jian=in.nextInt();
                 if(jian==z-y) {
                     System.out.println("对");
                    n++; 
                 }
                     else {
                         System.out.println("错"); 
                     }
             }
             else if(x==3) {
                
                 System.out.println(z+"乘"+y+"=");
                 System.out.println("请输入结果");
                 int cheng=in.nextInt();
                 if(cheng==z*y) {
                     System.out.println("对");
                    n++; 
                 }
                     else {
                         System.out.println("错"); 
                     }
             }
             else {
                 System.out.println(z+"除"+y+"=");
                 System.out.println("请输入结果");
                 int chu=in.nextInt();
                 if(chu==z/y) {
                     System.out.println("对");
                    n++; 
                 }
                     else {
                         System.out.println("错"); 
                     }
             }
             
         } 
         System.out.println("您做对的题数为"+n);

    }

}