写一个能自动生成三十道小学四则运算题目的 “软件”，新的要求： 可以控制下列参数: 是否有乘除法； 是否有括号(最多可以支持十个数参与计算)； 数值范围； 加减有无负数； 除法有无余数！
程序设计思想：
将要求的功能分别封装成类，在主函数中进行调用实现要求的功能。目前未能实现约分和多则运算，正在努力改进。
源代码：
package yunsuan;
import java.util.Scanner;
public class yunsuan {
public static void main(String[]args)
{
yunsuan a=new yunsuan();
System.out.println("请选择数值范围（最大值）");
Scanner in =new Scanner(System.in);
int range=in.nextInt();
System.out.println("请选择有无负数(1 or 2)");
int choose1=in.nextInt();
System.out.println("请选择有无乘除法(1 or 2)");
Scanner in3=new Scanner(System.in);
int choose2=in3.nextInt();
Scanner in1=new Scanner(System.in);
System.out.println("请输入要打印的数量");
int m=in1.nextInt();
for(int n=0;n<m;n++)
{
char[] c1={'+','-','*','/'};
int c=(int)(Math.random()*4);
if(choose1==1&&choose2==1)
{
if(c1[c]=='+')
{
a.add(range);
}
else if(c1[c]=='-')
{
a.jian2(range);
}
else if(c1[c]=='*')
{
a.chen(range);
}
else if(c1[c]=='/')
{
a.chu1(range);
}
}
else if((choose1==1&&choose2==2))
{
if(c1[c]=='+')
{
a.add(range);
}
else if(c1[c]=='-')
{
a.jian2(range);
}
else if(c1[c]=='*')
{
m++;
}
else if(c1[c]=='/')
{
m++;
}
}
else if((choose1==2&&choose2==2))
{
if(c1[c]=='+')
{
a.add(range);
}
else if(c1[c]=='-')
{
a.jian1(range);
}
else if(c1[c]=='*')
{
m++;
}
else if(c1[c]=='/')
{
m++;
}
}
else if((choose1==2&&choose2==1))
{
if(c1[c]=='+')
{
a.add(range);
}
else if(c1[c]=='-')
{
a.jian1(range);
}
else if(c1[c]=='*')
{
a.chen(range);
}
else if(c1[c]=='/')
{
a.chu1(range);
}
}
}
}
public void add(int range)
{
int answer=0;
int x=getrandom(range);
int y=getrandom(range);
System.out.print(x);
System.out.print('+');
System.out.print(y);
System.out.print("=");
System.out.println();
System.out.println("请输入答案：");
Scanner in2=new Scanner(System.in);
int q=in2.nextInt();
answer= x+ y;
System.out.println(answer);
if(q==answer)
{
System.out.println("回答正确！");
}
else
System.out.println("回答错误！");
}
public void jian1(int range)
{
int answer=0;
int x=getrandom(range);
int y=getrandom(range);
if( x> y)
{
System.out.print(x);
System.out.print('-');
System.out.print(y);
System.out.print("=");
System.out.println();
System.out.println("请输入答案：");
Scanner in2=new Scanner(System.in);
int q=in2.nextInt();
answer=x-y;
if(q==answer)
{
System.out.println("回答正确！");
}
else
System.out.println("回答错误！");
}
}
public void jian2(int range)
{
int answer=0;
int x=getrandom(range);
int y=getrandom(range);
System.out.print(x);
System.out.print('-');
System.out.print(y);
System.out.print("=");
System.out.println();
System.out.println("请输入答案：");
Scanner in2=new Scanner(System.in);
int q=in2.nextInt();
answer= x- y;
System.out.println(answer);
if(q==answer)
{
System.out.println("回答正确！");
}
else
System.out.println("回答错误！");
}
public void chu1(int range)
{
int answer=0;
int x=getrandom(range);
int y=getrandom(range);
System.out.print(x);
System.out.print('/');
System.out.print(y);
System.out.print("=");
System.out.println();
System.out.println("请输入答案：");
Scanner in2=new Scanner(System.in);
int q=in2.nextInt();
answer= x/y;
System.out.println(answer);
if(q==answer)
{
System.out.println("回答正确！");
}
else
System.out.println("回答错误！");
}
public void chen2(int range)
{
int answer=0;
int x=getrandom(range);
int y=getrandom(range);
if(x<y)
{
System.out.print(x);
System.out.print('*');
System.out.print(y);
System.out.print("=");
System.out.println();
System.out.println("请输入答案：");
Scanner in2=new Scanner(System.in);
int q=in2.nextInt();
answer= x*y;
System.out.println(answer);
if(q==answer)
{
System.out.println("回答正确！");
}
else
System.out.println("回答错误！");
}
}
public void chen(int range)
{
int answer=0;
int x=getrandom(range);
int y=getrandom(range);
System.out.print(x);
System.out.print('*');
System.out.print(y);
System.out.print("=");
System.out.println();
System.out.println("请输入答案：");
Scanner in2=new Scanner(System.in);
int q=in2.nextInt();
answer= x*y;
System.out.println(answer);
if(q==answer)
{
System.out.println("回答正确！");
}
else
System.out.println("回答错误！");
}
public int getrandom(int range)
{
int x=(int) ( Math.random() * range );
return x;
}
}
程序截图：
