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Set Matrix Zeroes

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Linkage

https://leetcode.com/problems/set-matrix-zeroes/description/

Solution

A traverse of will help us to mark which column or row should be marked as all zero. In this implementation, we will use O(m+n) space.

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class Solution {
    public void setZeroes(int[][] matrix) {
        int m = matrix.length;
        int n = matrix[0].length;
        boolean[] row_index = new boolean[m];
        boolean[] column_index = new boolean[n];
        for (int i = 0; i < m; i++){
            for (int j = 0; j < n; j++){
                if (matrix[i][j] == 0) {
                    row_index[i] = true;
                    column_index[j] = true;
                }
            }
        }
        for (int i = 0; i < m; ++i){
            if (row_index[i] == true){
                for (int k = 0; k < n; k++){
                    matrix[i][k] = 0;
                }
            }
        }
        
        for (int j = 0; j < n; ++j) {
            if (column_index[j] == true) {
                for (int k = 0; k < m; ++k) {
                    matrix[k][j] = 0;
                }
            }
        }
        
    }
}