用JAVA实现四则运算

木石流云

//产生随机的四则运算题目,输入答案,判断正误import java.util.*;import java.io.*;class suanshi{                //产生随机数//Random rand=new Random();//int a=(int)Math.random()*50;//int b=(int)Math.random()*20;//这样的数每次运行时都是一样的.//int c=(int)Math.random()*10+1;//rand.setSeed(long d);int a=(int)rand.nextInt()/1000000;int b=(int)rand.nextInt()/1000000;int c=(int)(rand.nextFloat()*10+1);public static double sum=0;//一定要声明为static的,否则后面的SUM就会为0public suanshi(){}char d;public suanshi(int k){                         //产生运算符号//if(1<=c&&c<=3){d='+';sum=a+b;}elseif(4<=c&&c<=6){d='-';sum=a-b;}elseif(7<=c&&c<=8){d='×';sum=a*b;}else {d='÷';sum=a/b;}System.out.print("("+a+")"+"  "+d+"  "+"("+b+")"+"=");}}class panduan extends suanshi {public static double count=0;  int result;public static int fens=0; panduan(){super(0);}public int  flag=0; panduan(int i){if(i==sum) {//if(i==(a+b)) {System.out.println("你答对了");flag=1;fens=fens+1;count=count+1;}else {System.out.println("你答错了"+"\n"+"不要放弃"+"\t");System.out.println("正确答案应该是:"+sum);flag=0;       // fens=fens-1;        count=count+1;}}int f0(){flag=0;return flag;}int f1(){flag=1;return flag;}}//主类开始//public class ceshi extends panduan{public int i=0;String s="";  ceshi(){ try{ BufferedReader in=new BufferedReader(new InputStreamReader(System.in)); s=in.readLine(); i=Integer.parseInt(s); }catch(NumberFormatException e){System.out.println("您输入的数字有误");} catch(IOException w){} panduan p=new panduan(i); }//int fc(){return i;} public static void main(String [] args) {int j=0;int tt=0;String ss="";System.out.println("这是四则运算题!");System.out.println("***************");System.out.println("第 "+(int)(count+1)+" 题");do{ceshi t=new ceshi();//int pp=t.fc();// t.panduan(pp);try{System.out.println("输入非1的数继续.输入1推出"); BufferedReader in=new BufferedReader(new InputStreamReader(System.in)); ss=in.readLine(); j=Integer.parseInt(ss); }catch(NumberFormatException e){System.out.println("您输入的数字有误");} catch(IOException w){}switch(j){case 0:tt=t.f0();System.out.println("==========================");System.out.println("第 "+(int)(count+1)+" 题");break;case 1:tt=t.f1();System.out.println("=%=%=%=%=%=%=%=%=%=%=%=%");System.out.println("您共做的"+count+"题，"+"其中答对"+fens+"题");            System.out.println("你的总分为:"+(fens/count)*100);          System.out.println("下次再努力哦!"+"\n"+"谢谢使用,再见^_^!");      System.out.println("*********************");break;}}while(tt==0);}}