{"id":1063337,"date":"2024-12-31T15:59:41","date_gmt":"2024-12-31T07:59:41","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/1063337.html"},"modified":"2024-12-31T15:59:45","modified_gmt":"2024-12-31T07:59:45","slug":"python-%e5%a6%82%e4%bd%95%e9%81%8d%e5%8e%86%e4%ba%8c%e5%8f%89%e6%a0%91","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/1063337.html","title":{"rendered":"python \u5982\u4f55\u904d\u5386\u4e8c\u53c9\u6811"},"content":{"rendered":"

\"python<\/p>\n

Python \u904d\u5386\u4e8c\u53c9\u6811\u7684\u65b9\u6cd5\u4e3b\u8981\u6709\uff1a\u524d\u5e8f\u904d\u5386\u3001\u4e2d\u5e8f\u904d\u5386\u3001\u540e\u5e8f\u904d\u5386\u3001\u5c42\u5e8f\u904d\u5386\u3002<\/strong> \u5176\u4e2d\uff0c\u524d\u5e8f\u904d\u5386\u662f\u6307\u5148\u8bbf\u95ee\u6839\u8282\u70b9\uff0c\u7136\u540e\u904d\u5386\u5de6\u5b50\u6811\uff0c\u6700\u540e\u904d\u5386\u53f3\u5b50\u6811\uff1b\u4e2d\u5e8f\u904d\u5386\u662f\u6307\u5148\u904d\u5386\u5de6\u5b50\u6811\uff0c\u7136\u540e\u8bbf\u95ee\u6839\u8282\u70b9\uff0c\u6700\u540e\u904d\u5386\u53f3\u5b50\u6811\uff1b\u540e\u5e8f\u904d\u5386\u662f\u6307\u5148\u904d\u5386\u5de6\u5b50\u6811\uff0c\u7136\u540e\u904d\u5386\u53f3\u5b50\u6811\uff0c\u6700\u540e\u8bbf\u95ee\u6839\u8282\u70b9\uff1b\u5c42\u5e8f\u904d\u5386\u662f\u6307\u6309\u5c42\u6b21\u9010\u5c42\u904d\u5386\u6811\u8282\u70b9\u3002\u4e0b\u9762\u5c06\u8be6\u7ec6\u4ecb\u7ecd\u6bcf\u79cd\u904d\u5386\u65b9\u6cd5\u3002<\/p>\n<\/p>\n

\u4e00\u3001\u524d\u5e8f\u904d\u5386<\/h3>\n<\/p>\n

\u524d\u5e8f\u904d\u5386\uff08Pre-order Traversal\uff09\u662f\u4e00\u79cd\u6df1\u5ea6\u4f18\u5148\u904d\u5386\u65b9\u6cd5\u3002\u524d\u5e8f\u904d\u5386\u7684\u987a\u5e8f\u662f\uff1a\u6839\u8282\u70b9 -> \u5de6\u5b50\u6811 -> \u53f3\u5b50\u6811\u3002<\/p>\n<\/p>\n

1. \u9012\u5f52\u5b9e\u73b0<\/h4>\n<\/p>\n

\u9012\u5f52\u5b9e\u73b0\u524d\u5e8f\u904d\u5386\u662f\u6700\u76f4\u63a5\u7684\u65b9\u6cd5\u3002\u901a\u8fc7\u9012\u5f52\u8c03\u7528\uff0c\u6211\u4eec\u53ef\u4ee5\u5f88\u7b80\u6d01\u5730\u5b9e\u73b0\u524d\u5e8f\u904d\u5386\u3002<\/p>\n<\/p>\n

class TreeNode:<\/p>\n
    def __init__(self, value=0, left=None, right=None):<\/p>\n
        self.value = value<\/p>\n
        self.left = left<\/p>\n
        self.right = right<\/p>\n
def preorder_traversal(root):<\/p>\n
    if root is None:<\/p>\n
        return []<\/p>\n
    return [root.value] + preorder_traversal(root.left) + preorder_traversal(root.right)<\/p>\n
\u793a\u4f8b<\/strong><\/h2>\n
root = TreeNode(1)<\/p>\n
root.left = TreeNode(2)<\/p>\n
root.right = TreeNode(3)<\/p>\n
root.left.left = TreeNode(4)<\/p>\n
root.left.right = TreeNode(5)<\/p>\n
print(preorder_traversal(root))<\/p>\n
<\/code><\/pre>\n<\/p>\n
2. \u8fed\u4ee3\u5b9e\u73b0<\/h4>\n<\/p>\n
\u4f7f\u7528\u6808\u7684\u8fed\u4ee3\u5b9e\u73b0\u4e5f\u53ef\u4ee5\u5b8c\u6210\u524d\u5e8f\u904d\u5386\u3002\u6808\u7528\u4e8e\u4fdd\u5b58\u8282\u70b9\uff0c\u6309\u7167\u201c\u6839 -> \u53f3 -> \u5de6\u201d\u7684\u987a\u5e8f\u538b\u5165\u6808\uff0c\u8fd9\u6837\u53ef\u4ee5\u4fdd\u8bc1\u51fa\u6808\u65f6\u7684\u987a\u5e8f\u662f\u201c\u6839 -> \u5de6 -> \u53f3\u201d\u3002<\/p>\n<\/p>\n
def preorder_traversal_iterative(root):<\/p>\n
    if root is None:<\/p>\n
        return []<\/p>\n
    stack, result = [root], []<\/p>\n
    while stack:<\/p>\n
        node = stack.pop()<\/p>\n
        result.append(node.value)<\/p>\n
        if node.right:<\/p>\n
            stack.append(node.right)<\/p>\n
        if node.left:<\/p>\n
            stack.append(node.left)<\/p>\n
    return result<\/p>\n
\u793a\u4f8b<\/strong><\/h2>\n
print(preorder_traversal_iterative(root))<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e8c\u3001\u4e2d\u5e8f\u904d\u5386<\/h3>\n<\/p>\n
\u4e2d\u5e8f\u904d\u5386\uff08In-order Traversal\uff09\u4e5f\u662f\u4e00\u79cd\u6df1\u5ea6\u4f18\u5148\u904d\u5386\u65b9\u6cd5\u3002\u4e2d\u5e8f\u904d\u5386\u7684\u987a\u5e8f\u662f\uff1a\u5de6\u5b50\u6811 -> \u6839\u8282\u70b9 -> \u53f3\u5b50\u6811\u3002<\/p>\n<\/p>\n
1. \u9012\u5f52\u5b9e\u73b0<\/h4>\n<\/p>\n
\u4e2d\u5e8f\u904d\u5386\u7684\u9012\u5f52\u5b9e\u73b0\u540c\u6837\u975e\u5e38\u76f4\u63a5\u3002<\/p>\n<\/p>\n
def inorder_traversal(root):<\/p>\n
    if root is None:<\/p>\n
        return []<\/p>\n
    return inorder_traversal(root.left) + [root.value] + inorder_traversal(root.right)<\/p>\n
\u793a\u4f8b<\/strong><\/h2>\n
print(inorder_traversal(root))<\/p>\n
<\/code><\/pre>\n<\/p>\n
2. \u8fed\u4ee3\u5b9e\u73b0<\/h4>\n<\/p>\n
\u8fed\u4ee3\u5b9e\u73b0\u4e2d\u5e8f\u904d\u5386\u9700\u8981\u501f\u52a9\u6808\u548c\u4e00\u4e2a\u6307\u9488\u3002\u901a\u8fc7\u4e0d\u65ad\u5c06\u5de6\u8282\u70b9\u538b\u5165\u6808\uff0c\u7136\u540e\u8bbf\u95ee\u6808\u9876\u5143\u7d20\uff0c\u518d\u8f6c\u5411\u53f3\u8282\u70b9\u3002<\/p>\n<\/p>\n
def inorder_traversal_iterative(root):<\/p>\n
    stack, result = [], []<\/p>\n
    current = root<\/p>\n
    while stack or current:<\/p>\n
        while current:<\/p>\n
            stack.append(current)<\/p>\n
            current = current.left<\/p>\n
        current = stack.pop()<\/p>\n
        result.append(current.value)<\/p>\n
        current = current.right<\/p>\n
    return result<\/p>\n
\u793a\u4f8b<\/strong><\/h2>\n
print(inorder_traversal_iterative(root))<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e09\u3001\u540e\u5e8f\u904d\u5386<\/h3>\n<\/p>\n
\u540e\u5e8f\u904d\u5386\uff08Post-order Traversal\uff09\u662f\u6df1\u5ea6\u4f18\u5148\u904d\u5386\u7684\u6700\u540e\u4e00\u79cd\u65b9\u6cd5\u3002\u540e\u5e8f\u904d\u5386\u7684\u987a\u5e8f\u662f\uff1a\u5de6\u5b50\u6811 -> \u53f3\u5b50\u6811 -> \u6839\u8282\u70b9\u3002<\/p>\n<\/p>\n
1. \u9012\u5f52\u5b9e\u73b0<\/h4>\n<\/p>\n
\u9012\u5f52\u5b9e\u73b0\u540e\u5e8f\u904d\u5386\u540c\u6837\u7b80\u5355\u3002<\/p>\n<\/p>\n
def postorder_traversal(root):<\/p>\n
    if root is None:<\/p>\n
        return []<\/p>\n
    return postorder_traversal(root.left) + postorder_traversal(root.right) + [root.value]<\/p>\n
\u793a\u4f8b<\/strong><\/h2>\n
print(postorder_traversal(root))<\/p>\n
<\/code><\/pre>\n<\/p>\n
2. \u8fed\u4ee3\u5b9e\u73b0<\/h4>\n<\/p>\n
\u540e\u5e8f\u904d\u5386\u7684\u8fed\u4ee3\u5b9e\u73b0\u7a0d\u5fae\u590d\u6742\u4e00\u4e9b\uff0c\u9700\u8981\u4f7f\u7528\u4e24\u4e2a\u6808\u3002<\/p>\n<\/p>\n
def postorder_traversal_iterative(root):<\/p>\n
    if root is None:<\/p>\n
        return []<\/p>\n
    stack1, stack2, result = [root], [], []<\/p>\n
    while stack1:<\/p>\n
        node = stack1.pop()<\/p>\n
        stack2.append(node)<\/p>\n
        if node.left:<\/p>\n
            stack1.append(node.left)<\/p>\n
        if node.right:<\/p>\n
            stack1.append(node.right)<\/p>\n
    while stack2:<\/p>\n
        result.append(stack2.pop().value)<\/p>\n
    return result<\/p>\n
\u793a\u4f8b<\/strong><\/h2>\n
print(postorder_traversal_iterative(root))<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u56db\u3001\u5c42\u5e8f\u904d\u5386<\/h3>\n<\/p>\n
\u5c42\u5e8f\u904d\u5386\uff08Level-order Traversal\uff09\u662f\u4e00\u79cd\u5e7f\u5ea6\u4f18\u5148\u904d\u5386\u65b9\u6cd5\u3002\u5c42\u5e8f\u904d\u5386\u6309\u5c42\u6b21\u4ece\u4e0a\u5230\u4e0b\u3001\u4ece\u5de6\u5230\u53f3\u4f9d\u6b21\u8bbf\u95ee\u8282\u70b9\u3002<\/p>\n<\/p>\n
1. \u4f7f\u7528\u961f\u5217\u5b9e\u73b0<\/h4>\n<\/p>\n
\u4f7f\u7528\u961f\u5217\u5b9e\u73b0\u5c42\u5e8f\u904d\u5386\u975e\u5e38\u81ea\u7136\uff0c\u961f\u5217\u5148\u8fdb\u5148\u51fa\u7684\u7279\u6027\u7b26\u5408\u5c42\u5e8f\u904d\u5386\u7684\u9700\u6c42\u3002<\/p>\n<\/p>\n
from collections import deque<\/p>\n
def level_order_traversal(root):<\/p>\n
    if root is None:<\/p>\n
        return []<\/p>\n
    queue, result = deque([root]), []<\/p>\n
    while queue:<\/p>\n
        level_size = len(queue)<\/p>\n
        level_nodes = []<\/p>\n
        for _ in range(level_size):<\/p>\n
            node = queue.popleft()<\/p>\n
            level_nodes.append(node.value)<\/p>\n
            if node.left:<\/p>\n
                queue.append(node.left)<\/p>\n
            if node.right:<\/p>\n
                queue.append(node.right)<\/p>\n
        result.append(level_nodes)<\/p>\n
    return result<\/p>\n
\u793a\u4f8b<\/strong><\/h2>\n
print(level_order_traversal(root))<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e94\u3001\u603b\u7ed3<\/h3>\n<\/p>\n
\u5728\u904d\u5386\u4e8c\u53c9\u6811\u65f6\uff0c\u9009\u62e9\u5408\u9002\u7684\u904d\u5386\u65b9\u6cd5\u53d6\u51b3\u4e8e\u5177\u4f53\u7684\u9700\u6c42\u3002\u524d\u5e8f\u904d\u5386<\/strong>\u9002\u7528\u4e8e\u9700\u8981\u5148\u5904\u7406\u6839\u8282\u70b9\u7684\u60c5\u51b5\uff0c\u4e2d\u5e8f\u904d\u5386<\/strong>\u9002\u7528\u4e8e\u9700\u8981\u6309\u987a\u5e8f\u5904\u7406\u8282\u70b9\u7684\u60c5\u51b5\uff0c\u540e\u5e8f\u904d\u5386<\/strong>\u9002\u7528\u4e8e\u9700\u8981\u5148\u5904\u7406\u5b50\u8282\u70b9\u7684\u60c5\u51b5\uff0c\u5c42\u5e8f\u904d\u5386<\/strong>\u9002\u7528\u4e8e\u6309\u5c42\u6b21\u5904\u7406\u8282\u70b9\u7684\u60c5\u51b5\u3002\u6bcf\u79cd\u904d\u5386\u65b9\u6cd5\u90fd\u6709\u5176\u72ec\u7279\u7684\u5e94\u7528\u573a\u666f\u548c\u5b9e\u73b0\u65b9\u5f0f\uff0c\u901a\u8fc7\u9012\u5f52\u548c\u8fed\u4ee3\u4e24\u79cd\u5b9e\u73b0\u65b9\u5f0f\uff0c\u6211\u4eec\u53ef\u4ee5\u7075\u6d3b\u5730\u5e94\u7528\u8fd9\u4e9b\u904d\u5386\u65b9\u6cd5\u6765\u89e3\u51b3\u5b9e\u9645\u95ee\u9898\u3002<\/p>\n<\/p>\n
\u5e0c\u671b\u4ee5\u4e0a\u5185\u5bb9\u80fd\u591f\u5e2e\u52a9\u4f60\u7406\u89e3\u548c\u638c\u63e1\u5982\u4f55\u5728Python\u4e2d\u904d\u5386\u4e8c\u53c9\u6811\u3002\u65e0\u8bba\u662f\u9012\u5f52\u8fd8\u662f\u8fed\u4ee3\uff0c\u6bcf\u79cd\u65b9\u6cd5\u90fd\u6709\u5176\u7279\u70b9\u548c\u9002\u7528\u573a\u666f\uff0c\u6839\u636e\u5177\u4f53\u9700\u6c42\u9009\u62e9\u5408\u9002\u7684\u65b9\u6cd5\u53ef\u4ee5\u63d0\u9ad8\u4ee3\u7801\u7684\u6548\u7387\u548c\u53ef\u8bfb\u6027\u3002<\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
 \u4e8c\u53c9\u6811\u904d\u5386\u7684\u57fa\u672c\u65b9\u6cd5\u6709\u54ea\u4e9b\uff1f<\/strong>
\u4e8c\u53c9\u6811\u904d\u5386\u901a\u5e38\u6709\u4e09\u79cd\u57fa\u672c\u65b9\u6cd5\uff1a\u524d\u5e8f\u904d\u5386\u3001\u4e2d\u5e8f\u904d\u5386\u548c\u540e\u5e8f\u904d\u5386\u3002\u524d\u5e8f\u904d\u5386\u662f\u5148\u8bbf\u95ee\u6839\u8282\u70b9\uff0c\u518d\u8bbf\u95ee\u5de6\u5b50\u6811\u548c\u53f3\u5b50\u6811\uff1b\u4e2d\u5e8f\u904d\u5386\u662f\u5148\u8bbf\u95ee\u5de6\u5b50\u6811\uff0c\u518d\u8bbf\u95ee\u6839\u8282\u70b9\uff0c\u6700\u540e\u8bbf\u95ee\u53f3\u5b50\u6811\uff1b\u540e\u5e8f\u904d\u5386\u5219\u662f\u5148\u8bbf\u95ee\u5de6\u5b50\u6811\uff0c\u518d\u8bbf\u95ee\u53f3\u5b50\u6811\uff0c\u6700\u540e\u8bbf\u95ee\u6839\u8282\u70b9\u3002\u6bcf\u79cd\u904d\u5386\u65b9\u5f0f\u5728\u4e0d\u540c\u573a\u666f\u4e0b\u90fd\u6709\u5176\u72ec\u7279\u7684\u5e94\u7528\u4ef7\u503c\u3002<\/p>\n
\u4f7f\u7528 Python \u904d\u5386\u4e8c\u53c9\u6811\u7684\u5e38\u89c1\u5b9e\u73b0\u65b9\u5f0f\u662f\u4ec0\u4e48\uff1f<\/strong>
\u5728 Python \u4e2d\uff0c\u904d\u5386\u4e8c\u53c9\u6811\u7684\u5e38\u89c1\u5b9e\u73b0\u65b9\u5f0f\u6709\u9012\u5f52\u548c\u975e\u9012\u5f52\u4e24\u79cd\u3002\u9012\u5f52\u65b9\u6cd5\u901a\u5e38\u66f4\u7b80\u6d01\u6613\u61c2\uff0c\u53ef\u4ee5\u901a\u8fc7\u7b80\u5355\u7684\u51fd\u6570\u8c03\u7528\u5b9e\u73b0\u4e0d\u540c\u7684\u904d\u5386\u65b9\u5f0f\u3002\u800c\u975e\u9012\u5f52\u65b9\u6cd5\u5219\u53ef\u4ee5\u4f7f\u7528\u6808\u6765\u6a21\u62df\u51fd\u6570\u8c03\u7528\u7684\u8fc7\u7a0b\uff0c\u9002\u5408\u5904\u7406\u66f4\u590d\u6742\u7684\u573a\u666f\u3002\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\uff0c\u9009\u62e9\u5408\u9002\u7684\u65b9\u6cd5\u53d6\u51b3\u4e8e\u5177\u4f53\u9700\u6c42\u548c\u6811\u7684\u89c4\u6a21\u3002<\/p>\n
\u5982\u4f55\u5904\u7406\u7a7a\u6811\u6216\u53f6\u5b50\u8282\u70b9\u7684\u60c5\u51b5\uff1f<\/strong>
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