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fix build_tree, binary_search_tree.cs

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fix two figures
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krahets
2023-09-15 02:08:09 +08:00
parent af2aeb0897
commit cb9c14f5ff
13 changed files with 69 additions and 72 deletions
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13
codes/python/chapter_divide_and_conquer/build_tree.py
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@ -12,8 +12,7 @@ from modules import *
def dfs(
preorder: list[int],
inorder: list[int],
hmap: dict[int, int],
inorder_map: dict[int, int],
i: int,
l: int,
r: int,
@ -25,11 +24,11 @@ def dfs(
# 初始化根节点
root = TreeNode(preorder[i])
# 查询 m ，从而划分左右子树
m = hmap[preorder[i]]
m = inorder_map[preorder[i]]
# 子问题：构建左子树
root.left = dfs(preorder, inorder, hmap, i + 1, l, m - 1)
root.left = dfs(preorder, inorder_map, i + 1, l, m - 1)
# 子问题：构建右子树
root.right = dfs(preorder, inorder, hmap, i + 1 + m - l, m + 1, r)
root.right = dfs(preorder, inorder_map, i + 1 + m - l, m + 1, r)
# 返回根节点
return root
@ -37,8 +36,8 @@ def dfs(
def build_tree(preorder: list[int], inorder: list[int]) -> TreeNode | None:
"""构建二叉树"""
# 初始化哈希表，存储 inorder 元素到索引的映射
hmap = {val: i for i, val in enumerate(inorder)}
root = dfs(preorder, inorder, hmap, 0, 0, len(inorder) - 1)
inorder_map = {val: i for i, val in enumerate(inorder)}
root = dfs(preorder, inorder_map, 0, 0, len(inorder) - 1)
return root