Posts

Showing posts with the label space complexity

73. Set Matrix Zeroes

Given a  m  x  n  matrix, if an element is 0, set its entire row and column to 0. Do it  in-place . Example 1: Input: [   [1,1,1],   [1,0,1],   [1,1,1] ] Output: [   [1,0,1],   [0,0,0],   [1,0,1] ] Example 2: Input: [   [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] ] Follow up: A straight forward solution using O( m n ) 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? --- Intuition We cannot flip every cell in row or column to zero when we encounter a zero, this would mean we potentially end up with a matrix of all zeros. We need to identify which cells are zero in the original matrix, and then use that information 1. O(m*n) solution - additional array which stores the right cell to flip bits on, and then parse tha...