四则运算

package 四则运算试题;
 
import java.io.BufferedReader;
import java.io.PrintStream;
import java.util.Scanner;
import java.io.FileReader;
import java.io.IOException;
public class jisuanti {
 
    public static void main(String[] args) throws IOException {
        int a1,a2;
        int b;
        int num=0;
        int i=0;
        //Scanner sc=new Scanner(System.in);
        String f[]=new String[4];
        f[0]="+";
        f[1]="-";
        f[2]="*";
        f[3]="/";
        int a[]=new int[100];
        //System.out.println("请选择100以内或1000以内");
        //m=sc.nextInt()+1;
        //System.out.println("请输入要产生的题数");
        //n=sc.nextInt();
        PrintStream out = System.out;
        PrintStream ps = new PrintStream("Test.txt");
        System.setOut(ps);
        for(i=0;i<3;i++)
        {
        a1=(int)(Math.random()*100);
        a2=(int)(Math.random()*100);
        b=(int)(Math.random()*4);
        System.out.println("第"+(i+1)+"题:"+a1+f[b]+a2+"=");
        System.out.println("*");
        switch(b) {
        case 0:a[i]=(a1+a2);break;
        case 1:a[i]=(a1-a2);break;
        case 2:a[i]=(a1*a2);break;
        case 3:a[i]=(a1/a2);break;
        }
        }
        ps.close();
         
        System.setOut(out);
        System.out.println("题目：");
        BufferedReader br = new BufferedReader(new FileReader("Test.txt"));
        String line = "";
        Scanner sc=new Scanner(System.in);
        int answer[]=new int[100];
        int m=0;
        while((line = br.readLine()) != null){
                if(line.charAt(0)=='*') {
                    System.out.print("请输入答案:");
                //  System.out.println(a[m]);
                    int n;
                    n=sc.nextInt();
                    answer[m]=n;
                    if(answer[m]==a[m])num++;
                    m++;
                }
                else {
                    System.out.println(line);
                }
                     
                 
        }
        sc.close();
        br.close();
        System.out.println("共答对"+num+"题");
    }
}