300道随机四则运算小程序（java编写）

import java.util.*;
class Yunsuan{
    public static void main(String[] args){
        Random rand = new Random();
        for(int i = 0; i < 300; i++){
            int num1 = (int)(rand.nextDouble() * 100);
            int num2 = (int)(rand.nextDouble() * 100);
            double num3 = 0;
            char ch = 0;
            switch(rand.nextInt(4)){
                case 0: ch = ‘+‘; num3 = 1.0 * num1 + num2; break;
                case 1: ch = ‘-‘; num3 = 1.0 * num1 - num2; break;
                case 2: ch = ‘ב; num3 = 1.0 * num1 * num2; break;
                case 3: ch = ‘÷‘; while(num2 == 0){num2 = (int)(rand.nextDouble() * 100);} num3 = 1.0 * num1 / num2; break;
            }
            num3 *= 100;
            num3 = Math.round(num3);
            num3 /= 100;
            if((num3 - (int)num3) == 0){
                System.out.println(num1 + "" + ch + num2 + "=" + (int)num3);
            }
            else{
                System.out.println(num1 + "" + ch + num2 + "=" + num3);
            }
        }

    }
}