LeetCode — Set Matrix Zeroes

Steven Lu
Jan 11, 2023

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Given an m x n integer matrix matrix, if an element is 0, set its entire row and column to 0's.

You must do it in place.

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

Follow up:

  • A straightforward 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?

Solution:

Time complexity: O(N²)

Space complexity: O(N²)

LC — Set Matrix Zeroes (Blind Curated 46)

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