SetMatrixZeros.java

import java.util.*;

public class SetMatrixZeros {
    public void setZeroes(int[][] matrix) {
        if (matrix.length == 0) return;

        boolean firstRowZero = false;
        boolean firstColZero = false;

        for (int i = 0; i < matrix[0].length; i++) {
            if (matrix[0][i] == 0) {
                firstRowZero = true;
                break;
            }
        }

        for (int i = 0; i < matrix.length; i++) {
            if (matrix[i][0] == 0) {
                firstColZero = true;
                break;
            }
        }

        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;
                    matrix[i][0] = 0;
                }
            }
        }

        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 (firstRowZero) {
            for (int i = 0; i < matrix[0].length; i++)
                matrix[0][i] = 0;
        }

        if (firstColZero) {
            for (int i = 0; i < matrix.length; i++)
                matrix[i][0] = 0;
        }
    }

    public void setZeroes1(int[][] matrix) {
        if (matrix.length == 0) return;

        int rows = matrix.length;
        int cols = matrix[0].length;
        Set<Integer> zeroRows = new HashSet<>();
        Set<Integer> zeroCols = new HashSet<>();
        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                if (matrix[i][j] == 0) {
                    zeroRows.add(i);
                    zeroCols.add(j);
                }
            }
        }

        for (int row : zeroRows) {
            for (int i = 0; i < cols; i++) matrix[row][i] = 0;
        }

        for (int col : zeroCols) {
            for (int i = 0; i < rows; i++) matrix[i][col] = 0;
        }

    }
}