题意: 输入一个正整数N(<=10),接着输入0~N-1每个结点的左右儿子结点,输出这颗二叉树的反转的层次遍历和中序遍历. AAAAAccepted code: #define HAVE_STRUCT_TIMESPEC #include<bits/stdc++.h> using namespace std; ][]; ]; void bfs(int r){ queue<int>q; q.push(r); cout<<r; while(!q.empty()){ in…

Given a binary tree, return the inorder traversal of its nodes' values. For example: Given binary tree [1,null,2,3], 1 \ 2 / 3 return [1,3,2]. Note: Recursive(递归) solution is trivial, could you do it iteratively(迭代)? 思路: 解法一:用递归方法很简单, (1)如果root为空,则返回…

Given a binary tree, return the inorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,3,2]. Note: Recursive solution is trivial, could you do it iteratively? confused what "{1,#,2,3}" means? > re…

给定一个二叉树,返回其中序遍历.例如:给定二叉树 [1,null,2,3],   1    \     2    /   3返回 [1,3,2].说明: 递归算法很简单,你可以通过迭代算法完成吗?详见:https://leetcode.com/problems/binary-tree-inorder-traversal/description/ Java实现: 递归实现: /** * Definition for a binary tree node. * public class TreeNo…

题意: 输入一个正整数N(<=20),接着输入N个结点的值,依次插入一颗AVL树,输出最终根结点的值. AAAAAccepted code: #define HAVE_STRUCT_TIMESPEC #include<bits/stdc++.h> using namespace std; ]; typedef struct node{ int val; node*left,*right; }; node*left_rotate(node*root){ node*tamp=root->…

题目描述 The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants.Given any two nodes in a binary tree, you are supposed to find their LCA. 最小共同祖先(LCA)是一棵树中两个节点U和V最深的那个公共父节点.要求给一棵树,以及两个节点,请你…

https://pintia.cn/problem-sets/994805342720868352/problems/1038430130011897856 The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. Given any two nodes in a binary tree, you are sup…

给定先序中序遍历的序列,可以确定一颗唯一的树 先序遍历第一个遍历到的是根,中序遍历确定左右子树 查结点a和结点b的最近公共祖先,简单lca思路: 1.如果a和b分别在当前根的左右子树,当前的根就是最近祖先 2.如果根等于a或者根等于b了,根就是最近祖先:判断和a等还是和b等就行了 3.如果都在左子树上,递归查左子树就可以了.这里找到左子树的边界和根(通过先序中序序列) 4.如果都在右子树上,递归查右子树. 代码1:不建树的做法,参考柳婼blog~ #include<bits/stdc++.h>…

1151 LCA in a Binary Tree (30 分) The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. Given any two nodes in a binary tree, you are supposed to find their LCA. Input Specification:…

题目 The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. Given any two nodes in a binary tree, you are supposed to find their LCA. Input Specification: Each input file contains one t…