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…

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…

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…

CF1208H Red Blue Tree 原本应该放在这里但是这题过于毒瘤..单独开了篇blog 首先考虑如果 $ k $ 无限小,那么显然整个树都是蓝色的.随着 $ k $ 逐渐增大,每个点都会有且仅有一次变色,我们考虑维护这个变色的时间 $ t $ .如果每个点的变色时间都已经被算出来,那么我们可以轻易解决题目的查询操作和修改 $ k $ , 也就是说修改 $ k $ 本身就是个假操作..只需要考虑的是修改单点颜色. 修改单点颜色,看起来就很 $ ddp $ .树链剖分后,用$ f(x)…

Red-Black trees are notorious for being nightmares of pointer manipulation. Instructors will show the theory, but won’t torture their students to implement one. Interviewers will avoid asking about it. They probably couldn’t do it themselves. You sho…

Implement the following operations of a queue using stacks. push(x) -- Push element x to the back of queue. pop() -- Removes the element from in front of queue. peek() -- Get the front element. empty() -- Return whether the queue is empty. Notes: You…

Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. empty() -- Return whether the stack is empty. Notes: You must use only s…

用队列实现栈.这个实现方法十分的简单,就是在push这一步的时候直接变成逆序. class MyStack { private: queue<int> q; queue<int> q2; public: /** Initialize your data structure here. */ MyStack() { } /** Push element x onto stack. */ void push(int x) { q.push(x); ;i<q.size()-;i++…

BaoBao has just found a rooted tree with n vertices and (n-1) weighted edges in his backyard. Among the vertices, of them are red, while the others are black. The root of the tree is vertex 1 and it's a red vertex.Let's define the cost of a red verte…

题意:一棵树上有m个红色结点,树的边有权值.q次查询,每次给出k个点,每次查询有且只有一次机会将n个点中任意一个点染红,令k个点中距离红色祖先距离最大的那个点的距离最小化.q次查询相互独立. 分析:数据量很... 最大值最小化,二分搜答案.将ST表求lca的dfs函数加一点东西,求出每个点到其最近红色祖先的距离.check函数中,枚举到其红色祖先的距离超过下限的点.设非法点数为p,尝试将其距离通过一次染色缩小.具体做法是求出这p个点的lca,这个点就是要染红的点,因为只有修改这个点,才有可能将所…