Set matrix zero if a row or column is zero

Overview

An m*n matrix is given. If an element is zero then set its row and column to zero

Examples

Input:

1, 1, 1 
0, 1, 1 
1, 1, 1

Output:

0, 1, 1 
0, 0, 0 
0, 1, 1

We will solve it by taking two additional arrays rowSet and columnSet of length m and n respectively. We will iterate through the matrix and

if matrix[i][j] == 0 then
   rowSet[i] = 1
   columnSet[j] = 1

We can then set matrix[i][j] to zero if rowSet[i] is equal to 1 or columenSet[j] is equal to 1

Program

Here is the program for the same.

package main

import "fmt"

func setZeroes(matrix [][]int) [][]int {
	numRows := len(matrix)

	numColumns := len(matrix[0])

	rowSet := make([]int, numRows)
	columnSet := make([]int, numColumns)

	for i := 0; i < numRows; i++ {
		for j := 0; j < numColumns; j++ {
			if matrix[i][j] == 0 {
				rowSet[i] = 1
				columnSet[j] = 1
			}
		}
	}

	for i := 0; i < numRows; i++ {
		for j := 0; j < numColumns; j++ {
			if rowSet[i] == 1 || columnSet[j] == 1 {

				matrix[i][j] = 0

			}
		}
	}

	return matrix

}

func main() {
	matrix := [][]int{{1, 1, 1}, {0, 1, 1}, {1, 1, 1}}
	output := setZeroes(matrix)
	fmt.Println(output)
}

Output

[[0 1 1] [0 0 0] [0 1 1]]