找到一個二維矩陣中所有包含0的，並且把0元素所在行與列全部轉換成0的演算法!

import java.util.ArrayList;

import java.util.List;

 

public class MatrixDemo {

 

// 找出二維矩陣中為0元素的所有集合

public static List<Posiztion> findZero(int a[][]) {

List<Posiztion> list = new ArrayList<Posiztion>();

int row = a.length;

int col = a[0].length;

for (int i = 0; i < row; i++) {

for (int j = 0; j < col; j++) {

if (a[i][j] == 0) {

Posiztion p = new Posiztion();

p.setX(i);

p.setY(j);

list.add(p);

}

}

}

return list;

}

 

// 將矩陣中的為0的元素的行與列全部替換為0

public static int[][] replaceZero(int a[][]) {

int b[][] = a;

List<Posiztion> l = findZero(a);

for (int i = 0; i < l.size(); i++) {

Posiztion p = l.get(i);

int x = p.getX();

int y = p.getY();

 

for (int j = 0; j < a.length; j++) {

b[j][y] = 0;

}

 

for (int k = 0; k < a[0].length; k++) {

b[x][k] = 0;

}

}

return b;

}

 

// 列印二維矩陣的函數

public static void printMatrix(int a[][]) {

for (int i = 0; i < a.length; i++) {

for (int j = 0; j < a[0].length; j++) {

System.out.print(a[i][j] + " ");

}

System.out.println();

}

}

 

public static void main(String[] args) {

int a[][] = { { 1, 2, 3, 4, 5 }, { 1, 2, 3, 4, 0 }, { 0, 1, 2, 3, 4 } ,{1,2,3,4,5}};

List<Posiztion> l = findZero(a);

System.out.println("The position of zero are:");

for (int i = 0; i < l.size(); i++) {

System.out.println("(" + l.get(i).getX() + "," + l.get(i).getY()

+ ")");

}

System.out.println("Before replace the Matrix is:");

printMatrix(a);

System.out.println("After replace the Matrix is:");

int b[][] = replaceZero(a);

printMatrix(b);

}

 

}

 

// 定義一個類,用來存放為0元素的位置,x代表在哪行，y代表在哪列

class Posiztion {

private int x;

private int y;

 

public int getX() {

return x;

}

 

public void setX(int x) {

this.x = x;

}

 

public int getY() {

return y;

}

 

public void setY(int y) {

this.y = y;

}

 

}

 

運行結果:

 

The position of zero are:

(1,4)

(2,0)

Before replace the Matrix is:

1 2 3 4 5 

1 2 3 4 0 

0 1 2 3 4 

1 2 3 4 5 

After replace the Matrix is:

0 2 3 4 0 

0 0 0 0 0 

0 0 0 0 0 

0 2 3 4 0