题目传送门 /* 找规律/贪心:ans = n - 01匹配的总数,水 */ #include <cstdio> #include <iostream> #include <algorithm> #include <cstring> #include <cmath> using namespace std; ; const int INF = 0x3f3f3f3f; char s[MAXN]; int main(void) //Codeforce…
Given a binary tree, find all leaves and then remove those leaves. Then repeat the previous steps until the tree is empty. Example:Given binary tree 1 / \ 2 3 / \ 4 5 Returns [4, 5, 3], [2], [1]. Explanation: 1. Remove the leaves [4, 5, 3] from the t…
Given a binary tree, find all leaves and then remove those leaves. Then repeat the previous steps until the tree is empty. Example: Given binary tree 1 / \ 2 3 / \ 4 5 Returns [4, 5, 3], [2], [1]. Explanation: 1. Remove the leaves [4, 5, 3] from the…
题意:找到离根结点最近的叶子结点的那一层(设同一层上的结点与根结点的距离相等),返回它所在的层数. 方法有: 1.递归深度搜索 2.层次搜索 方法一:递归(无优化) /** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ cla…
题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5573 这个题……规律暂时还找不到,先贡献两发TLE的代码吧,一个dfs一个状压枚举. #include <algorithm> #include <iostream> #include <iomanip> #include <cstring> #include <climits> #include <complex> #include &…
C. No to Palindromes! time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Paul hates palindromes. He assumes that string s is tolerable if each its character is one of the first p letters of th…
题意: 给出N个小时,分配这些小时去写若干份论文,若用1小时写一份论文,该论文会被引用A次,新写一篇论文的话,全面的论文会被新论文引用一次. 找最大的H,H是指存在H遍论文,而且这些论文各被引用大于H次. 思路: 第一步,我们要想怎么样分配这些时间,毫无疑问,当N个小时写N份论文时为最优方案. 证明如下:  如果一开始的A>数量的话,就一直写新的:(没疑问吧!!!,如果A>数量,你还写旧的不是浪费时间吗???)  然后我们就会到一个分水岭 到达 A=数量(这时还是可以接受的,因为这里的A也算进…
题目链接: http://acm.hust.edu.cn/vjudge/problem/48421 Binary Tree Time Limit: 3000MS 问题描述 Binary Tree is a tree data structure where each node has at most two children, usually they are distinguished as left and right child. And the node having the child…
Description In computer science, a binary tree is a tree data structure in which each node has at most two children. Consider an infinite full binary tree (each node has two children except the leaf nodes) defined as follows. For a node labelled v it…
Given a binary search tree (BST) with duplicates, find all the mode(s) (the most frequently occurred element) in the given BST. Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than or equal to the nod…
2037. Richness of binary words 题目连接: http://acm.timus.ru/problem.aspx?space=1&num=2037 Description For each integer i from 1 to n, you must print a string si of length n consisting of letters 'a' and 'b' only. The string si must contain exactly i dis…
<题目链接> 题目大意: 给定数字n,让你将其分成合数相加的形式,问你最多能够将其分成几个合数相加. 解题分析: 因为要将其分成合数相加的个数最多,所以自然是尽可能地将其分成尽可能小的合数相加的形式.通过找规律,我们能够发现,所有的偶数都能够分成4和6这两个合数的组合,而所有的奇数,在减去9这个最小的奇合数后,就会变成偶数,然后就是和普通偶数一样的处理方式. 普通偶数的处理方式就是,看他能够分成几个4,如果该偶数不为4的倍数,那么就是将其中的一个4换成6.总的最大合数个数为:$n/4$ 而奇数…
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 给定一个二叉树,寻找值最大的路径. 这个路径可以从这个树上面的任意一个节点开始,然后在任意一个节点结束. 例如: 给定下面的二叉树, 1 / \ 2 3 返回 6. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ G…
Binary Tree 题目连接: http://acm.hdu.edu.cn/showproblem.php?pid=5573 Description The Old Frog King lives on the root of an infinite tree. According to the law, each node should connect to exactly two nodes on the next level, forming a full binary tree. S…
前言 第一天的算法都还没有缓过来,直接就进入了第二天的算法学习.前一天一直在整理Binary Search的笔记,也没有提前预习一下,好在Binary Tree算是自己最熟的地方了吧(LeetCode上面Binary Tree的题刷了4遍,目前95%以上能够Bug Free)所以还能跟得上,今天听了一下,觉得学习到最多的,就是把Traverse和Divide Conquer分开来讨论,觉得开启了一片新的天地!今天写这个博客我就尽量把两种方式都写一写吧. Outline: 二叉树的遍历 前序遍历t…
[抄题]: We are given a binary tree (with root node root), a target node, and an integer value K. Return a list of the values of all nodes that have a distance K from the target node.  The answer can be returned in any order. Example 1: Input: root = [3…
[抄题]: Given a binary tree where every node has a unique value, and a target key k, find the value of the nearest leaf node to target k in the tree. Here, nearest to a leaf means the least number of edges travelled on the binary tree to reach any leaf…
[抄题]: Given a binary tree, write a function to get the maximum width of the given tree. The width of a tree is the maximum width among all levels. The binary tree has the same structure as a full binary tree, but some nodes are null. The width of one…
题目: Given inorder and postorder traversal of a tree, construct the binary tree. Note: You may assume that duplicates do not exist in the tree. 题解: 这道题跟pre+in一样的方法做,只不过找左子树右子树的位置不同而已. / \ / \ / \ 对于上图的树来说, index: 0 1 2 3 4 5 6 中序遍历为为了清晰表示,我给节点上了颜色,红色是…
Return any binary tree that matches the given preorder and postorder traversals. Values in the traversals pre and post are distinct positive integers. Example 1: Input: pre = [1,2,4,5,3,6,7], post = [4,5,2,6,7,3,1] Output: [1,2,3,4,5,6,7] Note: 1 <=…
One way to serialize a binary tree is to use pre-oder traversal. When we encounter a non-null node, we record the node's value. If it is a null node, we record using a sentinel value such as #. _9_ / \ 3 2 / \ / \ 4 1 # 6 / \ / \ / \ # # # # # # For…
Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1 / \ 2 3 Return 6. 这道求二叉树的最大路径和是一道蛮有难度的题,难就难在起始位置和结束位置可以为任意位置,我当然是又不会了,于是上网看看大神们的解法,看了很多人的都没太看明白,最后发现了网友Yu's…
Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], [15,7] ] 层序…
Problem: Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node. 初看本题第一印象为递归写法.首先找出终止条件:node == NULL.若未进入递归终止状态,则分左子树和又子树进行递归,最终返回累加最大的值.其代码如下: /*…
题目如下:https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/ Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. According to the definition of LCA on Wikipedia: “The lowest common ancestor is def…
Given a binary tree, find the maximum path sum from root. The path may end at any node in the tree and contain at least one node in it. 给一棵二叉树,找出从根节点出发的路径中,和最大的一条. 这条路径可以在任何二叉树中的节点结束,但是必须包含至少一个点(也就是根了). /** * Definition of TreeNode: * public class Tr…
Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes v and w as the lowest node in T that has both v and w…
Given a binary tree, find the length of the longest consecutive sequence path (连续的路径,不是从小到大). The path refers to any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The longest consecutive path ne…
Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. 找树的最大路径和 注意路径可以从任意点起始和结束. 我发现我真的还挺擅长树的题目的,递归不难.就是因为有个需要比较的量(最大和),所以需要再写一个函数. 因为路径可以从任意点起始和结束,所以每次递归的时候左右子树小于等于0的就可以不管了. #include <iostream> #include…
Binary Tree Level Order Traversal 题目描述: Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its level order…