>>> count_coins(None) 0
(node: TreeNode | None)
| 90 | return count_nodes(node.left) + count_nodes(node.right) + 1 |
| 91 | |
| 92 | def count_coins(node: TreeNode | None) -> int: |
| 93 | """ |
| 94 | >>> count_coins(None) |
| 95 | 0 |
| 96 | """ |
| 97 | if node is None: |
| 98 | return 0 |
| 99 | |
| 100 | return count_coins(node.left) + count_coins(node.right) + node.data |
| 101 | |
| 102 | if count_nodes(root) != count_coins(root): |
| 103 | raise ValueError("The nodes number should be same as the number of coins") |