import java.util.Random;
import java.util.Arrays;
public class Example {
public static void printMatrix(int[][] matrix) {
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 4; j++) {
System.out.printf("%3d", matrix[i][j]);
}
System.out.println();
}
System.out.println();
}
public static void setZeroes(int[][] matrix) {
int rows = matrix.length , cols = matrix[0].length;
int acol = 1;
for (int i = 0; i < rows; i++) {
for (int j = 0; j < cols; j++) {
if (matrix[i][j] == 0) {
matrix[i][0] = 0;
if (j != 0)
matrix[0][j] = 0;
else
acol = 0;
}
}
}
for (int i = 1; i < rows; i++) {
for (int j = 1; j < cols; j++) {
if (matrix[i][0] == 0 || matrix[0][j] == 0)
matrix[i][j] = 0;
}
}
if (matrix[0][0] == 0)
for (int j = 0; j < cols; j++) matrix[0][j] = 0;
if (acol == 0)
for (int i = 0; i < rows; i++) matrix[i][0] = 0;
}
private static int[][] createMtrixWithRandomNumbers(int rows, int cols) {
int[][] randomMatrix = new int[rows][cols];
Random rand = new Random();
rand.setSeed(System.currentTimeMillis());
for (int i = 0; i < rows; i++) {
for (int j = 0; j < cols; j++) {
Integer num = rand.nextInt() % 10;
randomMatrix[i][j] = Math.abs(num);
}
}
return randomMatrix;
}
public static void main(String[] args) {
int[][] randomMatrix = createMtrixWithRandomNumbers(4, 5);
printMatrix(randomMatrix);
setZeroes(randomMatrix);
printMatrix(randomMatrix);
}
}
/*
run1:
3 4 9 4
9 1 9 5
6 0 1 8
3 0 9 4
9 0 9 5
0 0 0 0
run2:
9 1 9 0
9 6 8 9
2 4 1 5
0 0 0 0
9 6 8 0
2 4 1 0
*/
