<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[IcePrincess_1968's World]]></title><description><![CDATA[I'll always miss you like a darling.]]></description><link>https://blog.youkuaiyun.com/IcePrincess_1968</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; IcePrincess_1968]]></copyright><item><title><![CDATA[BZOJ1177: Oil 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81489986</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81489986</guid><author>IcePrincess_1968</author><pubDate>Tue, 07 Aug 2018 22:41:44 +0800</pubDate><description><![CDATA[Description

采油区域 Siruseri政府决定将石油资源丰富的Navalur省的土地拍卖给私人承包商以建立油井。被拍卖的整块土地为一个矩形区域，被划分为M×N个小块。 Siruseri地质调查局有关于Navalur土地石油储量的估测数据。这些数据表示为M×N个非负整数，即对每一小块土地石油储量的估计值。 为了避免出现垄断，政府规定每一个承包商只能承包一个由K×K块相连的土地构成的正方...]]></description><category></category></item><item><title><![CDATA[Codeforces #1016B: Segment Occurences 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81433421</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81433421</guid><author>IcePrincess_1968</author><pubDate>Sun, 05 Aug 2018 17:46:24 +0800</pubDate><description><![CDATA[Description

You are given two strings s and t, both consisting only of lowercase Latin letters.The substring s[l..r] is the string which is obtained by taking characters sl,sl+1,…,sr without changing...]]></description><category></category></item><item><title><![CDATA[Codeforces #1016A: Death Note 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81433366</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81433366</guid><author>IcePrincess_1968</author><pubDate>Sun, 05 Aug 2018 17:40:36 +0800</pubDate><description><![CDATA[Description

You received a notebook which is called Death Note. This notebook has infinite number of pages. A rule is written on the last page (huh) of this notebook. It says: “You have to write name...]]></description><category></category></item><item><title><![CDATA[HDU6312: Game 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81263577</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81263577</guid><author>IcePrincess_1968</author><pubDate>Sat, 28 Jul 2018 17:54:07 +0800</pubDate><description><![CDATA[Description

Alice and Bob are playing a game. 
The game is played on a set of positive integers from 1 to n. 
In one step, the player can choose a positive integer from the set, and erase all of its ...]]></description><category></category></item><item><title><![CDATA[HDU6315:Naive Operations 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81255748</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81255748</guid><author>IcePrincess_1968</author><pubDate>Fri, 27 Jul 2018 23:38:23 +0800</pubDate><description><![CDATA[Description

In a galaxy far, far away, there are two integer sequence a and b of length n. 
b is a static permutation of 1 to n. Initially a is filled with zeroes. 
There are two kind of operations: ...]]></description><category></category></item><item><title><![CDATA[HDU6314: Matrix 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81255138</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81255138</guid><author>IcePrincess_1968</author><pubDate>Fri, 27 Jul 2018 22:28:55 +0800</pubDate><description><![CDATA[Description

Samwell Tarly is learning to draw a magical matrix to protect himself from the White Walkers. 
the magical matrix is a matrix with n rows and m columns, and every single block should be p...]]></description><category></category></item><item><title><![CDATA[BZOJ3282: Tree 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81228911</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81228911</guid><author>IcePrincess_1968</author><pubDate>Thu, 26 Jul 2018 22:30:49 +0800</pubDate><description><![CDATA[LCT的模板题，学splay和LCT合起来花了两三天 
LCT的核心就是用splay维护preferred path，preferred path定义为上次access操作所经过的那些边，access操作的本质是打通当前点到树的根 
这题要求删边，加边和维护一条链上的xor和 
对于加边(u,v)：makeroot(u)，fa[u]=v即可，注意虽然这时fa[u]=v，但是u并不是v的儿子，u和v...]]></description><category></category></item><item><title><![CDATA[HDU6305: RMQ Similar Sequence 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81176896</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81176896</guid><author>IcePrincess_1968</author><pubDate>Mon, 23 Jul 2018 23:41:24 +0800</pubDate><description><![CDATA[Description

Chiaki has a sequence A={a1,a2,…,an}. Let RMQ(A,l,r) be the minimum i (l≤i≤r) such that ai is the maximum value in al,al+1,…,ar.

Two sequences A and B are called \textit{RMQ Similar}, if...]]></description><category></category></item><item><title><![CDATA[SPOJ SUBLEX: Lexicographical Substring Search 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81164827</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81164827</guid><author>IcePrincess_1968</author><pubDate>Mon, 23 Jul 2018 11:26:04 +0800</pubDate><description><![CDATA[Description

Little Daniel loves to play with strings! He always finds different ways to have fun with strings! Knowing that, his friend Kinan decided to test his skills so he gave him a string S and ...]]></description><category></category></item><item><title><![CDATA[UOJ #275: 组合数问题 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81154461</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81154461</guid><author>IcePrincess_1968</author><pubDate>Sun, 22 Jul 2018 14:31:28 +0800</pubDate><description><![CDATA[非常好的题目，感觉这个lucas的应用算是常见套路了吧 
题目要求CMN≡0(modk)CNM≡0(modk)C_N^M\equiv0(modk)，因为k是质数，所以根据Lucas定理，CM/kN/k∗CMmodkNmodk≡0(modk)CN/kM/k∗CNmodkMmodk≡0(modk)C_{N/k}^{M/k}*C_{Nmodk}^{Mmodk}\equiv 0(modk) 
我们发现这个...]]></description><category></category></item><item><title><![CDATA[POJ1392: Ouroboros Snake 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81055364</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81055364</guid><author>IcePrincess_1968</author><pubDate>Sun, 15 Jul 2018 18:04:47 +0800</pubDate><description><![CDATA[Description

Ouroboros is a mythical snake from ancient Egypt. It has its tail in its mouth and continously devours itself.

The Ouroboros numbers are binary numbers of 2^n bits that have the property...]]></description><category></category></item><item><title><![CDATA[BZOJ3196: 二逼平衡树 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81048575</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81048575</guid><author>IcePrincess_1968</author><pubDate>Sat, 14 Jul 2018 23:11:20 +0800</pubDate><description><![CDATA[Description

您需要写一种数据结构（可参考题目标题），来维护一个有序数列，其中需要提供以下操作： 
1.查询k在区间内的排名 
2.查询区间内排名为k的值 
3.修改某一位值上的数值 
4.查询k在区间内的前驱(前驱定义为小于x，且最大的数) 
5.查询k在区间内的后继(后继定义为大于x，且最小的数)



Input

第一行两个数 n,m 表示长度为n的有序序列和m个操作 
第二行...]]></description><category></category></item><item><title><![CDATA[BZOJ2521: 最小生成树 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81038500</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81038500</guid><author>IcePrincess_1968</author><pubDate>Fri, 13 Jul 2018 22:34:48 +0800</pubDate><description><![CDATA[首先除了自己其他的边-1相当于给自己+1 
一件显然的事情是我们肯定不会给指定边做+1操作 
我们考虑什么时候指定边会不在最小生成树中，我们考虑kruskal的过程，是把边从小到大加入树中的，如果加到(a,b)的时候，a,b在并查集中是连通的，那么(a,b)就不会被加入，也就是说，如果存在一条路径，上面的每一条边权值都不大于w(a,b)，那么(a,b)就可能会不被加入，所以对于每一条可能的从a到b...]]></description><category></category></item><item><title><![CDATA[UOJ #316: 泳池 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81023870</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81023870</guid><author>IcePrincess_1968</author><pubDate>Thu, 12 Jul 2018 23:04:27 +0800</pubDate><description><![CDATA[我觉得这个dp还挺难的 
首先计算面积恰好为k的比较难办，不妨容斥，计算面积不大于k的，减去面积不大于k-1的就是恰好为k的 
对于一个段，我们关心的显然是最下面的危险区域，因为上面的对最终的矩形划分是没有影响的 
考虑dp[i][j]表示考虑宽度为j的区间，前i-1行都没有危险区域，第i行有危险区域，能圈出的最大面积不大于k的概率，这里的概率暂时不考虑1~i-1行都不危险的那部分的q的若干次方 ...]]></description><category></category></item><item><title><![CDATA[BZOJ4161: Shlw loves Matrixl 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81020214</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81020214</guid><author>IcePrincess_1968</author><pubDate>Thu, 12 Jul 2018 18:06:30 +0800</pubDate><description><![CDATA[如果把转移写成矩阵的形式做矩阵乘法，复杂度是O(k3logn)O(k3logn)O(k^3logn)的，不足以通过此题 
学习了一下这个noi2017用到的技巧：可以用矩阵的特征多项式优化常系数齐次线性递推



前置技能

特征多项式

矩阵AAA的特征多项式P(λ)=det∣λI−A∣P(λ)=det∣λI−A∣P(\lambda)=det\mid\lambda I-A\mid，它满足对于∀∀...]]></description><category></category></item><item><title><![CDATA[51Nod1766: 树上的最远点对 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81008500</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/81008500</guid><author>IcePrincess_1968</author><pubDate>Wed, 11 Jul 2018 23:16:04 +0800</pubDate><description><![CDATA[这题用到了树的直径的非常好的性质，有必要记录 
树的直径满足这样一个性质： 
设一棵树的一个点集SSS的直径的端点集合是{a1,b1a1,b1a_1,b_1}(如果有多条直径选取任意一条)，另一个点集TTT的直径的端点集合是{a2,b2a2,b2a_2,b_2}，则点集S⋃TS⋃TS\bigcup T的直径的端点集合{a3,b3a3,b3a_3,b_3}∈∈\in{a1,b1,a2,b2a1,b1...]]></description><category></category></item><item><title><![CDATA[POJ1637: Sightseeing tour 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/80955493</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/80955493</guid><author>IcePrincess_1968</author><pubDate>Sat, 07 Jul 2018 22:35:42 +0800</pubDate><description><![CDATA[感觉这个网络流的建图还是很妙的 
欧拉回路的判定肯定是所有点的入度=出度 
我们考虑刚开始随意给无向边定向，这样算出每个点的入度和出度 
我们改变一条有向边的方向，会使某个点度数+2，某个点度数-2，所以点的度数的奇偶性不变 
我们考虑这样建图：按照我们刚开始给无向边定的向反向连边，容量为1，对于d&amp;gt;0的点i，从s向i连流量为d/2的边，对于d&amp;lt;0的点i，从i向t连流量为-d/2的边，...]]></description><category></category></item><item><title><![CDATA[Codeforces #995F: Cowmpany Cowmpensation 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/80870355</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/80870355</guid><author>IcePrincess_1968</author><pubDate>Sat, 30 Jun 2018 21:46:55 +0800</pubDate><description><![CDATA[非常好的dp题 
首先可以参见topcoder randomapple的套路，就是我算这棵树的权值种数为i的方案数，最后乘CiDCDiC_D^i就好 
考虑dp[i][j]表示以i为根的子树，i的权值不超过j的方案数 
我们发现这样会重复计数，因为我们计算了一些本质相同的方案，比如全1和全2，他们各自在乘CiDCDiC_D^i的时候会把对方算进去 
所以我们实际上要算的是本质不同的方案数 
dp[...]]></description><category></category></item><item><title><![CDATA[Codeforces #838D: Airplane Arrangement 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/80869774</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/80869774</guid><author>IcePrincess_1968</author><pubDate>Sat, 30 Jun 2018 20:32:04 +0800</pubDate><description><![CDATA[一道神题 
考虑把座位拉成一个环，这样就不存在没有位置的情况了 
在第一个和最后一个之间加一个座位，这样只要这个座位被占就说明这个安排不合法 
我们发现这个环是完全对称的，所以每个位置被占的概率是一样的 
我们考虑所有的选法，现在有n+1个座位，有两种方向，所以有(2(n+1))m(2(n+1))m(2(n+1))^m种安排方式 
我们考虑选中合法方案的概率，从n+1个椅子里面挑m个被占，其中不能...]]></description><category></category></item><item><title><![CDATA[URAL1627: Join 题解]]></title><link>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/80780663</link><guid>https://blog.youkuaiyun.com/IcePrincess_1968/article/details/80780663</guid><author>IcePrincess_1968</author><pubDate>Sat, 23 Jun 2018 08:37:17 +0800</pubDate><description><![CDATA[把地图看成去掉障碍物的网格图，就可以用矩阵树定理直接算生成树个数了 
矩阵树定理： 
一个无向图的度数矩阵：di,j=degidi,j=degid_{i,j}=deg_i当且仅当i=ji=ji=j 
一个无向图的邻接矩阵：Ai,j=1Ai,j=1A_{i,j}=1当且仅当从iii到jjj有边 
一个无向图的基尔霍夫矩阵：Ki,j=di,j−Ai,jKi,j=di,j−Ai,jK_{i,j}=d_{...]]></description><category></category></item></channel></rss>