Set Matrix Zeroes

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public class Solution {    public void setZeroes(int[][] matrix) {        // O(1) space solution        // The first row and the first column        boolean firstRowHasZero = false, firstColHasZero = false;        for(int j = 0; j < matrix[0].length; j++) {            if(matrix[0][j] == 0) {                firstRowHasZero = true;                break;            }        }        for(int i = 0; i < matrix.length; i++) {            if(matrix[i][0] == 0) {                firstColHasZero = true;                break;            }        }        // Rest part        for(int i = 1; i < matrix.length; i++) {            for(int j = 1; j < matrix[0].length; j++) {                if(matrix[i][j] == 0) {                    matrix[0][j] = 0;   // Updates the first row                    matrix[i][0] = 0;   // Updates the first column;                }            }        }        // Clears the matrix according to the first row and the first column        // and the two booleans        for(int i = 1; i < matrix.length; i++) {            for(int j = 1; j < matrix[0].length; j++) {                if(matrix[0][j] == 0 || matrix[i][0] == 0) {                    matrix[i][j] = 0;                 }            }        }        if(firstRowHasZero) {            for(int j = 0; j < matrix[0].length; j++) {                matrix[0][j] = 0;            }        }        if(firstColHasZero) {            for(int i = 0; i < matrix.length; i++) {                matrix[i][0] = 0;            }        }    }}
Time: O(m * n)
Space: O(1)
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