USACO_2_4_Fractions to Decimals

一个简单的模拟题目，不过要小心括号的位置，做一点提示，用一个数组来记录每个余数出现的位置，如果出现了相同的余数那就发现了循环，上一次出现的地方就是左括号的位置，因为是模拟题，不建议看我的代码，所以就不写注释了

/**//*
ID: sdjllyh1
PROG: fracdec
LANG: JAVA
complete date: 2008/12/25
author: LiuYongHui From GuiZhou University Of China
more article: www.cnblogs.com/sdjls
*/

import java.io.*;
import java.util.*;

public class fracdec
{
    private static int n, d;
    private static int quotient, remainder;
    private static int[] decimals = new int[100000];
    private static int decimalLength = 0;
    private static int[] firstAppearance;
    private static int bracketPos = -1;

    public static void main(String[] args) throws IOException
    {
        init();
        run();
        output();
        System.exit(0);
    }

    private static void run()
    {
        quotient = n / d;
        remainder = n % d;

        if (remainder != 0)
        {
            firstAppearance[remainder] = 0;
            while ((remainder != 0) && (bracketPos == -1))
            {
                remainder *= 10;
                if (firstAppearance[remainder % d] == -1)
                {
                    decimals[decimalLength] = remainder / d;
                    decimalLength++;
                    firstAppearance[remainder % d] = decimalLength;
                    remainder %= d;
                }
                else
                {
                    decimals[decimalLength] = remainder / d;
                    decimalLength++;
                    bracketPos = firstAppearance[remainder % d];
                }
            }
        }
        else
        {
            decimalLength = 1;
        }
    }

    private static void init() throws IOException
    {
        BufferedReader f = new BufferedReader(new FileReader("fracdec.in"));
        StringTokenizer st = new StringTokenizer(f.readLine());
        n = Integer.parseInt(st.nextToken());
        d = Integer.parseInt(st.nextToken());
        firstAppearance = new int[d];
        Arrays.fill(firstAppearance, -1);
        f.close();
    }

    private static void output() throws IOException
    {
        PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("fracdec.out")));
        out.print(quotient + ".");
        int length = String.valueOf(quotient).length() + 1;
        for (int i = 0; i < decimalLength; i++)
        {
            if (i == bracketPos)
            {
                out.print('(');
                length++;
                if ((length + i) % 76 == 0)
                {
                    out.println();
                }
            }

            if (((length + i) % 76 == 0) && (i != decimalLength - 1))
            {
                out.println();
            }
            out.print(decimals[i]);
        }
        if (bracketPos != -1)
        {
            out.println(')');
        }
        else
        {
            out.println();
        }
        out.close();
    }
}