| 8 | } |
| 9 | |
| 10 | private Node dfs(int row, int column, int n) { |
| 11 | Node node = new Node(); |
| 12 | |
| 13 | if (areAllEqual(row, column, n)) { |
| 14 | node.isLeaf = true; |
| 15 | node.val = grid[row][column] == 1; |
| 16 | } else { |
| 17 | n /= 2; |
| 18 | node.isLeaf = false; |
| 19 | node.val = false; |
| 20 | |
| 21 | node.topLeft = dfs(row, column, n); |
| 22 | node.bottomLeft = dfs(row + n, column, n); |
| 23 | node.topRight = dfs(row, column + n, n); |
| 24 | node.bottomRight = dfs(row + n, column + n, n); |
| 25 | } |
| 26 | |
| 27 | return node; |
| 28 | } |
| 29 | |
| 30 | private boolean areAllEqual(int row, int column, int n) { |
| 31 | for (int i = 0; i < n; i++) { |