Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place.

Follow up:

Did you use extra space?

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?

思路

想法比较简单，把0所在的坐标记录下来，再把所有对应的行和列置为零即可。

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public class Solution {
    public void setZeroes(int[][] matrix) {
        List<Integer> lines = new ArrayList<Integer>();
        List<Integer> cols = new ArrayList<Integer>();
        for(int i = 0; i < matrix.length; i++){
            for(int j = 0; j < matrix[i].length; j++){
                if(matrix[i][j] == 0){
                    lines.add(i);
                    cols.add(j);
                }
            }
        }
        
        for(int i = 0; i < lines.size(); i++){
            int cur = lines.get(i);
            for(int j = 0; j < matrix[cur].length; j++){
                matrix[cur][j] = 0;
            }
        }
        
        for(int i = 0; i < cols.size(); i++){
            int cur = cols.get(i);
            for(int j = 0; j < matrix.length; j++){
                matrix[j][cur] = 0;
            }
        }
    }
}