bestcoder round#45 1003 题,给定两个点,要我们求这两个点的树上路径所经过的点的权值是否出现过奇数次.如果是一般人,那么就是用lca求树上路径,然后判断是否出现过奇数次(用异或),高手就不这么做了,直接树链剖分.为什么不能用lca,因为如果有树退化成链,那么每次询问的复杂度是O(n), 那么q次询问的时间复杂度是O(qn) 什么是树链剖分呢? 就是把树的边分成轻链和重链 http://blog.sina.com.cn/s/blog_6974c8b20100zc61.html…

1001 给定数n,要我们求该数的二进制中有多少组1, 相邻的1称为1组, 直接位运算摸你即可 #include <stdio.h> #include <string.h> #include <stdlib.h> #include <algorithm> #include <iostream> #include <queue> #include <stack> #include <vector> #includ…

BestCoder Round #16 题目链接 这场挫掉了,3挂2,都是非常sb的错误 23333 QAQ A:每一个数字.左边个数乘上右边个数,就是能够组成的区间个数,然后乘的过程注意取模不然会爆掉 B:dp,dp[i][2]记录下第一长的LIS,和第二长的LIS.哎,转移的时候一个地方写挫掉了导致悲剧啊QAQ C:首先假设知道Nim游戏的,就非常easy转化问题为.一些数字能否选几个能否异或和为0.那么就是每一个数字拆成40位.然后每一位异或和为0.这样就能够构造出40个方程,然后高斯消元…

Rikka with Phi  Accepts: 5  Submissions: 66  Time Limit: 16000/8000 MS (Java/Others)  Memory Limit: 131072/131072 K (Java/Others) Problem Description Rikka and Yuta are interested in Phi function (which is known as Euler's totient function). Yuta giv…

传送门 DZY Loves Topological Sorting Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 221    Accepted Submission(s): 52 Problem Description A topological sort or topological ordering of a directed…

1.BestCoder Round #89 2.总结:4个题,只能做A.B,全都靠hack上分.. 01  HDU 5944   水 1.题意:一个字符串,求有多少组字符y,r,x的下标能组成等比数列. 2.总结:有个坑,y,r,x顺序组公比q>1,也可反着来x,r,y顺序组. #include<iostream> #include<cstring> #include<cmath> #include<queue> #include<algorit…

BestCoder Round #90 本次至少暴露出三个知识点爆炸.... A. zz题 按题意copy  Init函数 然后统计就ok B. 博弈 题  不懂  推了半天的SG.....  结果这个题.... C 数据结构题   我写了半个小时分块   然后发现     改的是颜色.... 我的天  炸炸炸 D. 没看懂题目要干啥.....  官方题解要搞死小圆…

BestCoder Round #7 Start Time : 2014-08-31 19:00:00    End Time : 2014-08-31 21:00:00Contest Type : Register Public   Contest Status : Ended Current Server Time : 2014-08-31 21:12:12 Solved Pro.ID Title Ratio(Accepted / Submitted)   1001 Little Pony…

Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 354    Accepted Submission(s): 100 Problem Description ZYB has a tree with N nodes,now he wants you to solve the numbers of nodes distanced no m…

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 175    Accepted Submission(s): 74 Problem Description ZYB has a premutation P,but he only remeber the reverse log of each prefix of the premutat…