There is a kind of balanced binary search tree named red-black tree in the data structure. It has the following 5 properties: (1) Every node is either red or black. (2) The root is black. (3) Every leaf (NULL) is black. (4) If a node is red, then bot…

判断一棵树是否是红黑树,按题给条件建树,dfs判断即可~ #include<bits/stdc++.h> using namespace std; ; struct node { int data; node * left=NULL; node * right=NULL; }; void insert (node * &root,int x) { if (root==NULL) { root=new node; root->data=x; return; } if (abs(x)…

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>…

题目 A Binary Search Tree (BST) is recursively defined as a binary tree which has the following properties: The left subtree of a node contains only nodes with keys less than the node's key. The right subtree of a node contains only nodes with keys gre…

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…

转载自http://blog.csdn.net/yangjun2/article/details/6542321 介绍另一种平衡二叉树:红黑树(Red Black Tree),红黑树由Rudolf Bayer于1972年发明,当时被称为平衡二叉B树(symmetric binary B-trees),1978年被Leonidas J. Guibas 和 Robert Sedgewick改成一个比较摩登的名字:红黑树. 红黑树和之前所讲的AVL树类似,都是在进行插入和删除操作时通过特定操作保持二叉…

source address:http://en.wikipedia.org/wiki/Red%E2%80%93black_tree A red–black tree is a type of self-balancing binary search tree, a data structure used in computer science. The self-balancing is provided by painting each node with one of two colors…

小结: 1.红黑树:典型的用途是实现关联数组 2.旋转 当我们在对红黑树进行插入和删除等操作时,对树做了修改,那么可能会违背红黑树的性质.为了保持红黑树的性质,我们可以通过对树进行旋转,即修改树中某些结点的颜色及指针结构,以达到对红黑树进行插入.删除结点等操作时,红黑树依然能保持它特有的性质(五点性质). https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-046j-introduction-to-a…

PAT甲级:1066 Root of AVL Tree (25分) 题干 An AVL tree is a self-balancing binary search tree. In an AVL tree, the heights of the two child subtrees of any node differ by at most one; if at any time they differ by more than one, rebalancing is done to rest…

PAT甲级:1064 Complete Binary Search Tree (30分) 题干 A Binary Search Tree (BST) is recursively defined as a binary tree which has the following properties: The left subtree of a node contains only nodes with keys less than the node's key. The right subtre…