[Leetcode] [Java] Minimum Depth of Binary Tree

Title:

Given a binary tree, find its minimum depth.

The minimum depth is the number of nodes along, the shortest path from the root node to the nearest leaf node.

Test Instructions:

Given a binary tree, return its minimum height.

The minimum height refers to the number of nodes in the shortest path from the root node to the nearest leaf node.

Algorithm Analysis:

* with Heap

* Similar to the algorithm in Binary Tree level Order traversal

* If there is no self-band in the next layer, exit immediately and return the layer number of the layer

AC Code:

/** * Definition for a binary tree node.  * public class TreeNode {* int val, * TreeNode left, * TreeNode right; * TreeNode (int x) {val = x;} *} */public class Solution {public int mindepth (TreeNode root) {int Index=0;boolean flag=false; Arraylist<arraylist<integer>> res=new arraylist<arraylist<integer>> ();    arraylist<integer> list= new arraylist<integer> (); Linkedlist<treenode> que = new linkedlist<treenode> ();    if (Root==null) return 0;    Que.add (root);    while (que!=null) {TreeNode tem;    int size=que.size ();    List.clear ();    for (int i=0;i<size;i++) {tem=que.poll ();    List.add (Tem.val);    if (tem.left==null&&tem.right==null) {flag=true;//If there is no child node of the parent node, just jump out, statistics size break;    } if (Tem.left!=null) Que.add (tem.left);    if (tem.right!=null) Que.add (tem.right);    } res.add (new arraylist<integer> (list));    if (flag) return res.size ();    else Index=res.size ();} return index; }}

Copyright NOTICE: This article is the original article of Bo Master, reprint annotated source

[Leetcode] [Java] Minimum Depth of Binary Tree