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HomeJavajavaTutorialSolution to the problem of returning a sequence number array after sorting a two-dimensional array

MatrixElement class used by

package com.cdl.matrix;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
/**
 *@source:http://blog.csdn.net/justinavril/archive/2009/12/14/5003467.aspx
 * 
 *@function: 矩阵A
 * 
 *            68 36 22
 * 
 *            59 77 39
 * 
 *            81 20 17
 * 
 *            将矩阵A每列排序之后(升序排列)应该得到的矩阵是:
 * 
 *            矩阵B:
 * 
 *            59 20 17
 * 
 *            68 36 22
 * 
 *            81 77 39
 * 
 *            这样矩阵A中每个元素在矩阵B中对应的位置就是
 * 
 *            矩阵C:
 * 
 *            2 3 3
 * 
 *            1 1 1
 * 
 *            3 2 2
 * 
 *            问:由矩阵A得到矩阵C的算法?
 * 
 * @author ocaicai@yeah.net 2011-6-27
 * 
 */
public class MatrixColSort {
/**
* @param args
*/
public static void main(String[] args) {
int[][] initArray = { { 68, 36, 22 }, { 59, 77, 39 }, { 81, 20, 17 } };
System.out.println("原来的数组:");
printArray(initArray);
System.out.println("排序后的数组:");
MatrixElement[][] transferedArray = transferByElement(initArray);
MatrixElement[][] sortedArray = sortArrayCols(transferedArray);
int[][] targerArray = getRowsArray(sortedArray);
printArray(targerArray);
}
/**
* 将数组中单个的value转换成Element(value,rowIndex)
* 
* @param sourceArray
* @return
*/
public static MatrixElement[][] transferByElement(int[][] sourceArray) {
int rows = sourceArray.length;
int cols = sourceArray[0].length;
MatrixElement[][] elementArray = new MatrixElement[rows][cols];
for (int row = 0; row < rows; row++) {
for (int col = 0; col < cols; col++) {
elementArray[row][col] = new MatrixElement(
sourceArray[row][col], row + 1);
}
}
return elementArray;
}
/**
* 获取某一列的值存入一个临时的tempList中,
* 
* 然后对这个tempList赋整列的值然后对其排序,
* 
* 再把排序后的tempList赋值回列去
* 
* @param elementArray
*            被转换的对象
* @return
*/
public static MatrixElement[][] sortArrayCols(MatrixElement[][] elementArray) {
int rows = elementArray.length;
int cols = elementArray[0].length;
for (int colIndex = 0; colIndex < cols; colIndex++) {
List<MatrixElement> tempList = new ArrayList<MatrixElement>();
for (int rowIndex = 0; rowIndex < rows; rowIndex++) {
tempList.add(elementArray[rowIndex][colIndex]);
}
Collections.sort(tempList);
for (int rowIndex = 0; rowIndex < rows; rowIndex++) {
elementArray[rowIndex][colIndex] = tempList.get(rowIndex);
}
}
return elementArray;
}
/**
* @param elementArray
*            从其中获取rowIndex,做成一个数组返回去
* @return
*/
public static int[][] getRowsArray(MatrixElement[][] elementArray) {
int rows = elementArray.length;
int cols = elementArray[0].length;
int[][] rowArray = new int[rows][cols];
for (int row = 0; row < rows; row++)
for (int col = 0; col < cols; col++)
rowArray[row][col] = elementArray[row][col].getRowIndex();
return rowArray;
}
/**
* 打印二维数组
* 
* @param array
*/
public static void printArray(int[][] array) {
for (int i = 0; i < array.length; i++)
System.out.println(Arrays.toString(array[i]));
}
}

:

package com.cdl.matrix;
public class MatrixElement implements Comparable<MatrixElement> {
int value;
int rowIndex;
public int getValue() {
return value;
}
public void setValue(int value) {
this.value = value;
}
public int getRowIndex() {
return rowIndex;
}
public void setRowIndex(int rowIndex) {
this.rowIndex = rowIndex;
}
public MatrixElement(int value, int rowIndex) {
this.value = value;
this.rowIndex = rowIndex;
}
@Override
public int compareTo(MatrixElement anotherEmlement) {
//比较只需要对value比较
int valueCmp = this.value - anotherEmlement.value;
return valueCmp;
}
}

Output result:

原来的数组:
[68, 36, 22]
[59, 77, 39]
[81, 20, 17]
排序后的数组:
[2, 3, 3]
[1, 1, 1]
[3, 2, 2]


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