四则运算01

编写随机生成30道小学数学题目：

源代码：

package test;
public class  lianxi {String f(){int i = (int)(Math.random()*10);int j = (int)(Math.random()*10);if(i>j){int temp = i;i = j;j = temp;}return ("("+i+"/"+j+")");}
public static void main(String[] args){String a,b;int k;lianxi lianxi = new lianxi();for(int n=0;n<30;n++){a=lianxi.f();b=lianxi.f();int i=(int)(Math.random()*100);int j=(int)(Math.random()*100);switch((int)(Math.random()*4)){case 0:k = (int)(Math.random()*3);if(k==0)System.out.println(i+"+"+j+"=");else if(k==1)System.out.println(a+"+"+j+"=");else if(k==2)System.out.println(b+"+"+a+"=");break;case 1:k = (int)(Math.random()*3);if(i<j){int temp=i;i=j;j=temp;}if(k==0)System.out.println(i+"-"+j+"=");else if(k==1)System.out.println(j+"-"+a+"=");else if(k==2)System.out.println(b+"-"+a+"=");break;case 2:k = (int)(Math.random()*3);if(k==0)System.out.println(i+"*"+j+"=");else if(k==1)System.out.println(a+"*"+j+"=");else if(k==2)System.out.println(b+"*"+a+"=");break;case 3:while(j==0)j=(int)(Math.random()*100);System.out.println(i+"/"+j+"=");break;}}
}
}

结果截图：