Given an m x n matrix. If an element is 0, set its entire row and column to 0. Do it in-place.
Follow up:
A straight forward solution using O(mn) space is probably a bad idea.
A simple improvement uses O(m + n) space, but still not the best solution.
Could you devise a constant space solution?
Example 1:
Input: matrix = [[1,1,1],[1,0,1],[1,1,1]]
Output: [[1,0,1],[0,0,0],[1,0,1]]
Example 2:
Input: matrix = [[0,1,2,0],[3,4,5,2],[1,3,1,5]]
Output: [[0,0,0,0],[0,4,5,0],[0,3,1,0]]
Constraints:
m == matrix.length
n == matrix[0].length
1 <= m, n <= 200
-231 <= matrix[i][j] <= 231 - 1
public class Solution {
public void SetZeroes(int[][] matrix) {
var setRow = new HashSet<int>();
var setCol = new HashSet<int>();
for(int i=0;i<matrix.Length;i++){
for(int j=0;j<matrix[0].Length;j++){
if(matrix[i][j]==0){
setRow.Add(i);
setCol.Add(j);
}
}
}
for(int i=0;i<matrix.Length;i++){
for(int j=0;j<matrix[0].Length;j++){
if(setRow.Contains(i) || setCol.Contains(j)){
matrix[i][j]=0;
}
}
}
}
}
Time Complexity: O(n^2)
Space Complexity: O(n)