四则运算缓冲流

最新推荐文章于 2025-09-09 09:10:31 发布

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最新推荐文章于 2025-09-09 09:10:31 发布

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CC 4.0 BY-SA版权

文章标签： java

原文链接：http://www.cnblogs.com/my---world/p/9965846.html

本文通过一个Java程序实例，演示了如何进行数学运算并生成随机算术题，同时实现了将运算过程及结果输出到文件，以及从文件中读取数据并与用户输入进行比较的全过程。详细介绍了在Java中使用FileInputStream、FileOutputStream、PrintStream和Scanner等类进行文件操作的方法，以及如何处理除法运算结果的小数位问题。

package sizeyuansuan;
import java.io.*;
import java.util.*;
public class Sizeyuansuan {
    public static void main(String[] args)throws IOException
    {
        FileOutputStream outfile= new FileOutputStream(new File("sizeyuansuan.txt"));
        PrintStream printStream= new PrintStream(outfile);
        FileInputStream infile= new FileInputStream("sizeyuansuan.txt");
        InputStreamReader reader = new InputStreamReader(infile, "UTF-8");
         StringBuffer buffer = new StringBuffer();
        Scanner in=new Scanner(System.in);
        int a=0;
        int b=0;
        int sum;
        int count=0;
        double[] num=new double[100];
        int i;
        for(i=0;i<100;i++)
        {
            a= (int)(Math.random()*10+1);
            b=(int)(Math.random()*10+1);
            int number=(int)(Math.random()*30);
            if(number%4==0)
            {
                sum=a+b;
                printStream.print(a);
                printStream.print("+");
                printStream.print(b);
                printStream.print("=");
                printStream.print(sum);
                printStream.append("\r\n");
                num[i]=sum;
            }
            if(number%4==1)
            {
                sum=a-b;
                printStream.print(a);
                printStream.print("-");
                printStream.print(b);
                printStream.print("=");
                printStream.print(sum);
                printStream.append("\r\n");
                num[i]=sum;
            }
            if(number%4==2)
            {
                sum=a*b;
                printStream.print(a);
                printStream.print("*");
                printStream.print(b);
                printStream.print("=");
                printStream.print(sum);
                printStream.append("\r\n");
              num[i]=sum;
            }
            if(number%4==3)
            {
                sum=a/b;
                printStream.print(a);
                printStream.print("/");
                printStream.print(b);
                printStream.print("=");
                printStream.print(sum);
                printStream.append("\r\n");
                num[i]=sum;
            }
        }
        printStream.close();
        int test;
        double Sum;
        for(i=0;i<100;i++)
        {
        while ((test= reader.read()) != '=')
        {
            System.out.print((char)test);
        }
        Sum=in.nextDouble();
        if(Sum==num[i])
        {
            System.out.println("ture");
            count++;
        }
        else
        {
            System.out.println("false");
        }
        }
        System.out.println("ture:"+count+"   false:"+(100-count));
        reader.close();
    }
}