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62 lines
1.2 KiB
Markdown
Executable File
62 lines
1.2 KiB
Markdown
Executable File
# [111. Minimum Depth of Binary Tree](https://leetcode.com/problems/minimum-depth-of-binary-tree/)
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## 题目
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Given a binary tree, find its minimum depth.
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The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.
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**Note**: A leaf is a node with no children.
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**Example**:
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Given binary tree `[3,9,20,null,null,15,7]`,
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3
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/ \
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9 20
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/ \
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15 7
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return its minimum depth = 2.
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## 题目大意
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给定一个二叉树，找出其最小深度。最小深度是从根节点到最近叶子节点的最短路径上的节点数量。说明: 叶子节点是指没有子节点的节点。
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## 解题思路
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- 递归求出根节点到叶子节点的深度，输出最小值即可
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## 代码
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```go
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package leetcode
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/**
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* Definition for a binary tree node.
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* type TreeNode struct {
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* Val int
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* Left *TreeNode
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* Right *TreeNode
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* }
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*/
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func minDepth(root *TreeNode) int {
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if root == nil {
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return 0
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}
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if root.Left == nil {
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return minDepth(root.Right) + 1
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}
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if root.Right == nil {
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return minDepth(root.Left) + 1
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}
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return min(minDepth(root.Left), minDepth(root.Right)) + 1
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}
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``` |