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锁定老帖子 主题：一个关于字串的排序算法~~
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发表时间：2009-03-19
有如下一些数据：
1-2-3-4-5 2-3-2 2-4-4-2 1-6 保存在一个文本文档中（ANSI编码格式）。要求排序成如下结果： 1-6 1-2-3-4-5 2-4-4-2 2-3-2 即以每一行的最后一个元素进行排序，如果相同再以之前一个排序。都是降序。。 有兴趣的可以试试。 package com.watersoft.file;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class Sort {
private int lineCount;
private int numberCount;
private String path;
private int[][] matrix;
/**
* *
*
* @param args
* contains the path of a text file which include the data being
* sorted
*/
public static void main(String[] args) {
if (args.length < 1) {
System.err.println("Specific a file please!");
return;
}
System.out.println(">>> Information: sort start ..\n");
Sort s = new Sort();
s.setPath(args[0]);
s.doSort();
s.display();
System.out.println("\n>>> Information: sort end ..");
}
/** * do sort: initialize, parse, then sort. */
public void doSort() {
init();
parse();
for (int index = 0; index < this.lineCount - 1; index++)
for (int innerIndex = 0; innerIndex < this.lineCount - 1; innerIndex++)
sort(innerIndex, this.numberCount - 1);
}
/**
* * sort the given data according to the given row index and column index *
*
* @param rowIndex
* current row *
* @param colIndex
* current column
*/
private void sort(int rowIndex, int colIndex) {
int aInt = this.matrix[rowIndex][colIndex];
int bInt = this.matrix[rowIndex + 1][colIndex];
int temp = 0;
if (aInt < bInt) { /* * swap two rows */
for (int index = 0; index < this.numberCount; index++) {
temp = this.matrix[rowIndex][index];
this.matrix[rowIndex][index] = this.matrix[rowIndex + 1][index];
this.matrix[rowIndex + 1][index] = temp;
}
} else if (aInt == bInt) { /* * compare previous elements of two rows */
colIndex--;
sort(rowIndex, colIndex);
}
}
/**
* * read file to make sure the dimension of matrix *
*
* @return boolean value, true if successfully done, else false
*/
private boolean init() {
try {
FileReader fr;
fr = new FileReader(this.path);
BufferedReader br = new BufferedReader(fr);
String tempString;
int lc = 0;
int nc = 0;
while ((tempString = br.readLine()) != null) {
lc++;
nc = (nc < tempString.split("-").length) ? tempString
.split("-").length : nc;
}
this.lineCount = lc;
this.numberCount = nc;
} catch (FileNotFoundException e) {
System.err.println("Error: cannot find file:[" + this.path + "]");
return false;
} catch (IOException e) {
System.err.println("Error: cannot read file..");
return false;
}
return true;
}
private boolean parse() { /* * initialize matrix */
this.matrix = new int[this.lineCount][this.numberCount];
for (int index = 0; index < this.lineCount; index++)
for (int innerIndex = 0; innerIndex < this.numberCount; innerIndex++)
this.matrix[index][innerIndex] = Integer.MAX_VALUE;
try {
FileReader fr;
fr = new FileReader(this.path);
BufferedReader br = new BufferedReader(fr);
String tempString;
String[] tempArray;
int lc = 0;
int baseIndex = 0;
while ((tempString = br.readLine()) != null) {
tempArray = tempString.split("-");
baseIndex = this.numberCount - tempArray.length;
for (int index = baseIndex; index < this.numberCount; index++)
this.matrix[lc][index] = Integer.parseInt(tempArray[index
- baseIndex]);
lc++;
}
} catch (FileNotFoundException e) {
System.err.println("Error: cannot find file:[" + this.path + "]");
return false;
} catch (IOException e) {
System.err.println("Error: cannot read file..");
return false;
}
return true;
}
/** * display sorted result */
public void display() {
for (int index = 0; index < this.lineCount; index++) {
for (int innerIndex = 0; innerIndex < this.numberCount; innerIndex++) {
if (this.matrix[index][innerIndex] != Integer.MAX_VALUE)
if (innerIndex + 1 != this.numberCount)
System.out.print(this.matrix[index][innerIndex] + "-");
else
System.out.print(this.matrix[index][innerIndex]);
}
System.out.println();
}
}
public void setPath(String path) {
this.path = path;
}
}
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发表时间：2009-08-04
最后修改：2009-08-04
package test;
import java.io.BufferedReader;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
public class StringSort {
public static void main(String[] args){
StringSort ss = new StringSort();
//you'd better judge the null
List<String> number = ss.sortString(ss.readString());
ss.printResult(number);
}
//read string from file
private List<String> readString(){
List<String> initString = new ArrayList<String>();
try {
BufferedReader readFile = new BufferedReader(new FileReader("C://string.txt"));
String tempstring;
while(null != (tempstring = readFile.readLine())){
initString.add(ConvertString(tempstring));
}
return initString;
}catch (Exception e) {
e.printStackTrace();
return null;
}
}
// reverse and delete '-' from string
private String ConvertString(String number){
String[] tempSting = number.split("-");
List<String> tempList = new ArrayList<String>();
for(int i=tempSting.length-1;i>=0;i--){
tempList.add(tempSting[i]);
}
return tempList.toString();
}
// sort the List
private List<String> sortString(List<String> list){
List<String> result = new ArrayList<String>();
//sort
Collections.sort(list);
//reverse
Collections.reverse(list);
// result collection
for(int i=0;i<list.size();i++){
String temp = list.get(i).replaceAll("\\D", "");
StringBuffer sb= new StringBuffer();
for(int index = temp.length()-1; index>=0;index--){
sb.append(temp.charAt(index));
sb.append(0 == index ?"":"-");
}
result.add(sb.toString());
}
return result;
}
//print the result
private void printResult(List<String> number){
Iterator i = number.iterator();
while(i.hasNext()){
System.out.println(i.next());
}
}
}
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发表时间：2009-09-04
我觉得有一个最好的办法：
思路：1.先将每个字符串赋值给一个String； 、 2.讲String集体给byte[] 4.根据byte的最后一个字符的值来比较；这样很方便； |
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发表时间：2009-12-15
我想到一个方法不知道可以不？
把数字补齐，然后反方向变成long，比较大小，按照比较后的顺序把原文排序。 说明： 1-2-3-4-5 2-3-2 2-4-4-2 1-6 补齐： 1-2-3-4-5① 0-0-2-3-2② 0-2-4-4-2③ 0-0-0-1-6④ 反向变成long： 54321 23200 24420 61000 排序： 61000④ 54321① 24420③ 23200② |
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