diff --git a/problems/0513.找树左下角的值.md b/problems/0513.找树左下角的值.md index 391118ab..17d15fde 100644 --- a/problems/0513.找树左下角的值.md +++ b/problems/0513.找树左下角的值.md @@ -274,9 +274,8 @@ class Solution { Python: - -**递归法 - 回溯** ```python +//递归法 # Definition for a binary tree node. # class TreeNode: # def __init__(self, val=0, left=None, right=None): @@ -285,53 +284,17 @@ Python: # self.right = right class Solution: def findBottomLeftValue(self, root: TreeNode) -> int: - max_depth = -float("INF") - max_left_value = -float("INF") - - def __traversal(root, left_len): - nonlocal max_depth, max_left_value - - if not root.left and not root.right: - if left_len > max_depth: - max_depth = left_len - max_left_value = root.val - return - - if root.left: - left_len += 1 - __traversal(root.left, left_len) - left_len -= 1 - - if root.right: - left_len += 1 - __traversal(root.right, left_len) - left_len -= 1 - return - - __traversal(root, 0) - - return max_left_value -``` - -**迭代法 - 层序遍历** -```python -class Solution: - def findBottomLeftValue(self, root: TreeNode) -> int: - queue = deque() - if root: - queue.append(root) - result = 0 - while queue: - q_len = len(queue) - for i in range(q_len): - if i == 0: - result = queue[i].val - cur = queue.popleft() - if cur.left: - queue.append(cur.left) - if cur.right: - queue.append(cur.right) - return result + depth=0 + self.res=[] + def level(root,depth): + if not root:return + if depth==len(self.res): + self.res.append([]) + self.res[depth].append(root.val) + level(root.left,depth+1) + level(root.right,depth+1) + level(root,depth) + return self.res[-1][0] ``` Go: