题解 | #清除行列#

清除行列，最主要的还是识别行和列，存入列表

    public int[][] clearZero(int[][] mat, int n) {
        HashSet<Integer> setRow = new HashSet<>();
        HashSet<Integer> setCol = new HashSet<>();
        // write code here
        for (int i = 0; i < n; i ++) {
            for (int j = 0; j < n; j ++) {
                if (mat[i][j] == 0) {
                    setRow.add(i);
                    setCol.add(j);
                }
            }
        }
        int[][] result = new int[n][n];
        for (int i = 0; i < n; i ++) {
            for (int j = 0; j < n; j ++) {
                if (setRow.contains(i)) {
                    result[i][j] = 0;
                } else if (setCol.contains(j)) {
                    result[i][j] = 0;
                } else {
                    result[i][j] = mat[i][j];
                }
            }
        }
        return result;
    }
     
}