cggghh的博客

文章目录2019-2020 ACM-ICPC Pacific Northwest Regional Contest (Div. 1)B.Perfect FlushC.Coloring ContentionD.Dividing By TwoE.Rainbow StringsI.Error CorrectionL.Carry Cam FailureM.Maze Connect2019-2020 ACM-ICPC Pacific Northwest Regional Contest (Div. 1)AB

2022/3/4文章目录A. ParityB. TapeC. Meaningless OperationsD. JongmahE. Magic StonesF. Nearest LeafA. Parity题意：求n=a1∗bk−1+a2∗bk−2+...+akn=a_1*b^{k-1}+a_2*b^{k-2}+...+a_kn=a1​∗bk−1+a2​∗bk−2+...+ak​的奇偶性。题解：考虑b的奇偶性，若b为偶数，则前k-1项必为偶数，此时只用判断aka_kak​奇偶性。若b为奇数，n的

Codeforces Round #538 Div.2A.Got Any Grapes?B. Yet Another Array Partitioning TaskC. Trailing Loves (or L'oeufs?)D. Flood FillE. Arithmetic ProgressionF. Please, another Queries on Array?A.Got Any Grapes?题意：由三个人，第一个人需要x个a葡萄，第二个人需要y个a葡萄或b葡萄，第三个人需要z个a，b，c

A. Deletions of Two Adjacent LettersB. DIV + MODC. Weight of the System of Nested SegmentsD. Twist the PermutationE. Rescheduling the ExamF. Vitaly and Advanced Useless AlgorithmsG. Counting ShortcutsA. Deletions of Two Adjacent Letters题意：给你一个字符串，一次可以删.

题意：把所有nnn元排列按字典序从小到大排成一列，求其中有多少子串为mmm元排列,ttt组询问。题解：(1)考虑单个nnn元组中的mmm元组个数。将mmm元组看成一个元素，排列组合有m!m!m!的情况，现在共有(n−m+1)(n-m+1)(n−m+1)个元素，排列组合为(n−m+1)!(n-m+1)!(n−m+1)!。共有m!(n−m+1)!m!(n-m+1)!m!(n−m+1)!的mmm元组。(2)考虑跨两个nnn元组的mmm元组个数。假设kkk为某个排列中的最后一个使得pk<pk+1&

@[TOC](Codeforces Round #546 (Div. 2))A.Nastya Is Reading a Book题意：一本书共有nnn章，每章为[li,ri][l_i,r_i][li​,ri​],现在读到kkk页，问剩下没读得包括当前章的章数。题解：遍历一遍看第kkk页再第几章，ans=n−k+1ans=n-k+1ans=n−k+1int l[111],r[111];int main() { ios::sync_with_stdio(0); cin.tie(0); cout.t

A. Petr题意：给定一个字符串S，问以stat字符串开头，以end字符串结尾的子字符串有多少种，若完全一样视为一种。题解：考虑双哈希，以哈希值来判断字符串相等，可以达到n2n^2n2复杂度。wa点：对于end字符串，他的开头下表jjj应该大于等于stat的开头下标iii并且j+len2−1>=i+len1−1j+len2-1>=i+len1-1j+len2−1>=i+len1−1。然后赛时一直T68，因为开了个map，在否循环里判断map里是否已经有这个合法字符串，这样就多

A. Game题意：你只能跳一次，可以从1的地方跳到任意1的地方，消耗的值为距离差，问最小消耗多少。题解：从前面最后的1跳到后面最前的1.#include <cstdio>#include <cmath>#include <algorithm>#include <iostream>#include <cstring>#include <map>#include <string>#include &lt

Codeforces Round #779 Div.2A.Marin and PhotoshootB.Marin and Anti-coprime PermutationC.Shinju and the Lost PermutationD1.388535 (Easy Version)D2.388535 (Hard Version)E.Gojou and Matrix GameF.Juju and Binary StringA.Marin and Photoshoot题意：有一串01串，0代表男生，1代表

A. Sasha and His TripB. Sasha and Magnetic MachinesC. Sasha and a Bit of RelaxD. Sasha and One More NameF. Sasha and Interesting Fact from Graph TheoryA. Sasha and His Trip题意：从1号城市到n号城市，每过一个城市消耗一升油，在i城市加油的代价为i每升。油箱最多v升油，问到n号城市的最小代价。题解：在最前面几个城市加最多的油，最.

文章目录ICL 2016A Three seamarksD CamelogisticsF GCD and LCMG PotsH MessengerI Manhattan ProjectM The smallest fractionICL 2016ABCD (√)EF (√)G (√)H (√)I (√)JKLM (√)A Three seamarks给出点M1,M2,M3的坐标,和角M1KM2,M2KM3的大小,求点K的坐标D Camelogistics题意：骆驼要把

C.Positions in Permutations题意：若∣p[i]−i∣=1|p[i]-i|=1∣p[i]−i∣=1,则这是一个完美位置。问nnn个位置恰好有kkk个完美位置的方案数。设F(m)F(m)F(m)代表固定mmm个完美位置，G(m)G(m)G(m)代表恰好有mmm个完美位置。∑i=0n(−1)i(ni)=0=[n=0]\sum_{i=0}^n(-1)^i\tbinom{n}{i}=0=[n=0]∑i=0n​(−1)i(in​)=0=[n=0]F(m)=∑i=mn(im)G(i)F

文章目录ICPC 2019-2020 North-Western Russia Regional ContestA.Accurate MovementB.Bad TreapE.EquidistantI.Ideal PyramidJ.Just the Last DigitM.Managing DifficultiesICPC 2019-2020 North-Western Russia Regional ContestA (√)(√)(√)B (√)(√)(√)CDE (√)(√)(√)FG