标签：arr String ++ ArrayList 笔记 int 拆分 new 排序

import java.io.*;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Random;

public class Test02 {
    public static void main(String[] args) throws Exception {
        pxData();
    }
    //数据排序
    public static void pxData() throws Exception {
        ArrayList<String> list = new ArrayList<>();
        //文件数组
        File[] files = new File[10];
        for (int i = 0; i < 10; i++) {
            files[i] = new File("C:\\Users\\KONG\\Desktop\\data"+ (i+1) +".txt");
        }
        for (int i = 0; i < files.length ; i++) {
            //建立输入流读取文件
            FileReader fr = new FileReader(files[i]);
            char[] c = new char[12];
            while (fr.read(c) != -1){
                list.add(new String(c).substring(0, 11));
            }
            fr.close();
            //集合转数组
            String[] arr = list.toArray(new String[0]);
            System.out.println("排序前 ：" + Arrays.toString(arr));
            // 排序
            arr= px1(arr);
            System.out.println("排序后 ：" + Arrays.toString(arr));
            //数据写回文档
            FileWriter fw = new FileWriter(files[i]);
            for (int j = 0; j < arr.length; i++) {
                fw.write(arr[j] + "\n");
                fw.flush();
            }
            fw.close();
        }
        System.out.println("排序完成");
    }
    //数据写回
    private static void outData(File file, String[] arr) throws IOException {
        
    }
    //桶排序
    public static String[] px1(String[] arr){
        ArrayList<String> list0 = null;
        ArrayList<String> list1 = null;
        ArrayList<String> list2 = null;
        ArrayList<String> list3 = null;
        ArrayList<String> list4 = null;
        ArrayList<String> list5 = null;
        ArrayList<String> list6 = null;
        ArrayList<String> list7 = null;
        ArrayList<String> list8 = null;
        ArrayList<String> list9 = null;
        for (int i = 10; i >= 0; i--) {
            list0 = new ArrayList<>();
            list1 = new ArrayList<>();
            list2 = new ArrayList<>();
            list3 = new ArrayList<>();
            list4 = new ArrayList<>();
            list5 = new ArrayList<>();
            list6 = new ArrayList<>();
            list7 = new ArrayList<>();
            list8 = new ArrayList<>();
            list9 = new ArrayList<>();
            for (int j = 0; j < arr.length; j++) {
                switch (arr[j].substring(i, i+1)) {
                    case ("0"):
                        list0.add(arr[j]);
                        break;
                    case ("1"):
                        list1.add(arr[j]);
                        break;
                    case ("2"):
                        list2.add(arr[j]);
                        break;
                    case ("3"):
                        list3.add(arr[j]);
                        break;
                    case ("4"):
                        list4.add(arr[j]);
                        break;
                    case ("5"):
                        list5.add(arr[j]);
                        break;
                    case ("6"):
                        list6.add(arr[j]);
                        break;
                    case ("7"):
                        list7.add(arr[j]);
                        break;
                    case ("8"):
                        list8.add(arr[j]);
                        break;
                    case ("9"):
                        list9.add(arr[j]);
                        break;
                }
            }
            int k = 0,j= 0;
            while (j < list0.size()){
                arr[k++] = list0.get(j++);
            }
            j = 0;
            while (j < list1.size()){
                arr[k++] = list1.get(j++);
            }
            j = 0;
            while (j < list2.size()){
                arr[k++] = list2.get(j++);
            }
            j = 0;
            while (j < list3.size()){
                arr[k++] = list3.get(j++);
            }
            j = 0;
            while (j < list4.size()){
                arr[k++] = list4.get(j++);
            }
            j = 0;
            while (j < list5.size()){
                arr[k++] = list5.get(j++);
            }
            j = 0;
            while (j < list6.size()){
                arr[k++] = list6.get(j++);
            }
            j = 0;
            while (j < list7.size()){
                arr[k++] = list7.get(j++);
            }
            j = 0;
            while (j < list8.size()){
                arr[k++] = list8.get(j++);
            }
            j = 0;
            while (j < list9.size()){
                arr[k++] = list9.get(j++);
            }
        }
        return arr;
    }
    /**
     *快速排序算法（不稳定排序）不可用于基数排序
     */
    public static String[] px(String[] arr, int begin, int end, int num){
        if(begin < end) {
            Integer pivot = Integer.valueOf(arr[end].substring(num, num + 1));
            int i = begin, j = begin;
            while (j < end) {
                int now = Integer.valueOf(arr[j].substring(num, num + 1));
                if (now < pivot) {
                    String temp = arr[i];
                    arr[i] = arr[j];
                    arr[j] = temp;
                    i++;
                }
                j++;
            }
            if (j == end) {
                String temp = arr[end];
                arr[end] = arr[i];
                arr[i] = temp;
            }
            px(arr, begin, i - 1,num);
            px(arr, i + 1, end,num);
        }
        return arr;
    }

    //创建数据
    public static void cData() throws Exception {
        File file = new File("C:\\Users\\KONG\\Desktop\\data01.txt");
        if (!file.exists())  file.createNewFile();
        PrintWriter out
                = new PrintWriter(new BufferedWriter(new FileWriter(file,true)));
        for (int i = 0; i < 10000; i++) {
            String dataOut = "1" + String.format("%02d",new Random().nextInt(99))
                    + String.format("%04d",new Random().nextInt(9999))
                    + String.format("%04d",new Random().nextInt(9999)) + "\n";
            out.write(dataOut);
            out.flush();
        }
        out.close();
    }
    //数据拆分
    public static void cfData() throws Exception {
        File file = new File("C:\\Users\\KONG\\Desktop\\data01.txt");
        FileReader fr = new FileReader(file);
        String fileName = "C:\\Users\\KONG\\Desktop\\data1.txt";
        PrintWriter pw = new PrintWriter(new FileWriter(new File(fileName),false));
        int num = 1;
        int time = 0;
        char[] c = new char[12];
        while (fr.read(c) != -1){
            pw.write(c);
            pw.flush();
            time++;
            if(time%1000 == 0){
                num ++;
                pw = new PrintWriter(new FileWriter(
                        new File(fileName.substring(0,fileName.length()-5) +num+ ".txt"),false));
            }
        }
        pw.close();
        System.out.println("拆分完成！");
    }
}

标签：arr,String,++,ArrayList,笔记,int,拆分,new,排序
来源： https://blog.csdn.net/kong34215247/article/details/122645012

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