题解 | #矩阵置零#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param matrix int整型ArrayList<ArrayList<>> 
     */
    public void setZeroMatrix (ArrayList<ArrayList<Integer>> matrix) {
        int m = matrix.size();
        int n = matrix.get(0).size();
        boolean[][] dp = new boolean[m][n];
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                if (matrix.get(i).get(j) == 0){
                    process1(dp, i, j);
                }
            }
        }
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                if (dp[i][j] == true){
                    matrix.get(i).set(j, 0);
                }
            }
        }
    }
    public static void process1(boolean[][] matrix, int x, int y){
        for (int i = 0; i < matrix.length; i++) {
            matrix[i][y] = true;
        }
        for (int j = 0; j < matrix[0].length; j++) {
            matrix[x][j] = true;
        }
    }
}