题:https://codeforces.com/contest/1099/problem/F 题意:给定一个树,每个节点有俩个信息x和t,分别表示这个节点上的饼干个数和先手吃掉这个节点上一个饼干的的时间.然后有先手和后手俩个人. ◉先手可以这么操作:在规定总时间T到达某个节点然后一定要返回根节点1,期间可以选择吃掉某些节点上的某些饼干(前提是保证剩下的时间能够回到根节点): ◉后手可以这么操作:在先手到达的位置和这个位置的孩子之间的连边选择一条让先手吃得更多的边摧毁掉,也可以跳过这个过程: 问…

F - Cookies 思路:我们先考虑如何算出在每个节点结束最多能吃多少饼干, 这个dfs的时候用线段树维护一下就好了, 然后有个这个信息之后树上小dp一下就好啦. #include<bits/stdc++.h> #define LL long long #define fi first #define se second #define mk make_pair #define PLL pair<LL, LL> #define PLI pair<LL, int> #…

Codeforces Round #620 F2. Animal Observation (hard version) (dp + 线段树) 题目链接 题意 给定一个nm的矩阵,每行取2k的矩阵,求总共矩阵里的数的和最大值,重复取到的数不算 题解 dp[i]表示当前行从第i个数开始取矩阵的最大值 dp[i] = 上一行中最大数 + 当前行第i个数到第i+k-1个数的和 - 当前行重复的 + 下一行第i个数到第i+k-1个数的和 用线段树维护 上一行中最大数 + 当前行第i个数到第i+k-1个数的…

F. Cookies 链接:http://codeforces.com/contest/1099/problem/F 题意: 给你一棵树,树上有n个节点,每个节点上有ai块饼干,在这个节点上的每块饼干需要花费bi时间,有两个玩家,玩家一可以移动到当前点的子节点也可以申请游戏结束返回根节点并吃沿途的饼干,玩家二可以删除当前点到儿子节点的一条边,走路和吃饼干都消耗时间,会给出一个总时间,在总时间内尽可能的多吃饼干,问最多能吃多少个? 思路: 由于是玩家一先手,那么最开始的最大边则不会被删除,但之后路…

https://codeforces.com/contest/1099/problem/F 题意 一颗n个节点的树上,每个点都有\(x[i]\)个饼干,然后在i节点上吃一个饼干的时间是\(t[i]\),有n-1条边,每条边有边权w为经过一条边所需时间,你从树根开始先手向下走,然后对手割掉你所在节点到子节点的任意一条边,你可以在任何时间选择返回,在返回的过程中你可以选择性吃掉经过节点的饼干,问在双方最优的情况下,你最多能在T时间之内吃掉多少饼干并返回根节点(在足够时间返回根节点的情况下吃掉尽可能多…

D. Valid Sets time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output As you know, an undirected connected graph with n nodes and n - 1 edges is called a tree. You are given an integer d and a tree…

题目链接:http://codeforces.com/contest/610/problem/D 就是给你宽度为1的n个线段,然你求总共有多少单位的长度. 相当于用线段树求面积并,只不过宽为1,注意y和x的最大都要+1,这样才相当于求面积. #include <iostream> #include <cstdio> #include <cstring> #include <map> #include <algorithm> using names…

题目地址:http://codeforces.com/contest/474/problem/E 第一次遇到这样的用线段树来维护DP的题目.ASC中也遇到过,当时也非常自然的想到了线段树维护DP,可是那题有简单方法,于是就没写.这次最终写出来了.. 这题的DP思想跟求最长上升子序列的思想是一样的.仅仅只是这里的找前面最大值时会超时,所以能够用线段树来维护这个最大值,然后因为还要输出路径,所以要用线段树再来维护一个每一个数在序列中所在的位置信息. 手残了好多地方,最终调试出来了... 代码例如以下…

链接: https://codeforces.com/contest/1234/problem/D 题意: You are given a string s consisting of lowercase Latin letters and q queries for this string. Recall that the substring s[l;r] of the string s is the string slsl+1-sr. For example, the substrings…

C. Drazil and Park 题目连接: http://codeforces.com/contest/516/problem/C Description Drazil is a monkey. He lives in a circular park. There are n trees around the park. The distance between the i-th tree and (i + 1)-st trees is di, the distance between t…

题目链接: http://codeforces.com/problemset/problem/444/C J. DZY Loves Colors time limit per test:2 secondsmemory limit per test:256 megabytes 问题描述 DZY loves colors, and he enjoys painting. On a colorful day, DZY gets a colorful ribbon, which consists of…

D. Vika and Segments 题目连接: http://www.codeforces.com/contest/610/problem/D Description Vika has an infinite sheet of squared paper. Initially all squares are white. She introduced a two-dimensional coordinate system on this sheet and drew n black hor…

题目链接:http://codeforces.com/problemset/problem/242/E 给你n个数,m个操作,操作1是查询l到r之间的和,操作2是将l到r之间的每个数xor与x. 这题是线段树成段更新,但是不能直接更新,不然只能一个数一个数更新.这样只能把每个数存到一个数组中,长度大概是20吧,然后模拟二进制的位操作.仔细一点就行了. #include <iostream> #include <cstdio> #include <cmath> #incl…

E. Kefa and Watch Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/580/problem/E Description One day Kefa the parrot was walking down the street as he was on the way home from the restaurant when he saw something glittering b…

题目:http://codeforces.com/problemset/problem/356/A 题意:首先给你n,m,代表有n个人还有m次描述,下面m行,每行l,r,x,代表l到r这个区间都被x所击败了(l<=x<=r),被击败的人立马退出游戏让你最后输出每个人是被谁击败的,最后那个胜利者没被 人击败就输出0 思路:他的每次修改的是一个区间的被击败的人,他而且只会记录第一次那个被击败的人,用线段树堕落标记的话他会记录最后一次的,所以我们倒着来修改, 然后因为那个区间里面还包含了自己,在线段…

E. A Simple Task 题目连接: http://www.codeforces.com/contest/558/problem/E Description This task is very simple. Given a string S of length n and q queries each query is on the format i j k which means sort the substring consisting of the characters from…

题目链接:http://codeforces.com/contest/381/problem/E  E. Sereja and Brackets time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Sereja has a bracket sequence s1, s2, ..., sn, or, in other words, a…

题目链接: http://codeforces.com/problemset/problem/558/E E. A Simple Task time limit per test5 secondsmemory limit per test512 megabytes 问题描述 This task is very simple. Given a string S of length n and q queries each query is on the format i j k which mea…

题目地址:传送门 这题尽管是DIV1的C. . 可是挺简单的. .仅仅要用线段树分别维护一下横着和竖着的值就能够了,先离散化再维护. 每次查找最大的最小值<=tmp的点,能够直接在线段树里搜,也能够二分去找. 代码例如以下: #include <iostream> #include <string.h> #include <math.h> #include <queue> #include <algorithm> #include <…

题意 给定一棵以 \(1\) 号点为根的树.若满足以下条件,则认为节点 \(p\) 处有一个 \(k\) 叉高度为 \(m\) 的堆: 若 \(m = 1\) ,则 \(p\) 本身就是一个 \(k\) 叉高度为 \(1\) 的堆. 若 \(m > 1\) ,则 \(p\) 需要有至少 \(k\) 个儿子满足在儿子处有一个 \(k\) 叉高度为 \(m − 1\) 的堆. 令 \(dp[p][k]\) 表示在 \(p\) 点 \(k\) 叉堆的最大高度,令 \(g[p][k]\) 为 \(p\)…

F. Economic Difficulties An electrical grid in Berland palaces consists of 2 grids: main and reserve. Wires in palaces are made of expensive material, so selling some of them would be a good idea! Each grid (main and reserve) has a head node (its num…

#define HAVE_STRUCT_TIMESPEC#include <bits/stdc++.h>using namespace std;int val[300007],num[300007],ans=0;vector<int>v[300007];void dfs(int u){ if(v[u].size()==0){ num[u]=1; ans++; return; } int tmp=0; for(int i=0;i<v[u].size();i++){ int vv…

#include<bits/stdc++.h>using namespace std;const int N=200005;int n,A[N];long long Mx,tot,S[N];vector<int>Adj[N];void DFS(int v,int p){    S[v]=A[v];    for(int &u:Adj[v])        if(u!=p)            DFS(u,v),S[v]+=S[u];    if(p)//0号结点是不存在的…

题意:给你一个长度为\(n\)的序列,求一个最长的\({x,x+1,x+2,.....,x+k-1}\)的序列,输出它的长度以及每个数在原序列的位置. 题解:因为这题有个限定条件,最长序列是公差为\(1\)的单增序列,所以其实非常简单. ​ 我们用\(map\)来记录每个元素最后出现的位置,\(dp\)表示当前位置的最长序列,\(last\)表示\(x-1\)的位置. ​ \(dp\)状态有两种更新方式: 1.如果上个元素\((x-1)\)存在,则\(dp[i]=dp[x-1]+1\). ​ 2…

E. Sasha and Array 题目连接: http://codeforces.com/contest/719/problem/E Description Sasha has an array of integers a1, a2, ..., an. You have to perform m queries. There might be queries of two types: 1 l r x - increase all integers on the segment from l…

E. Memory and Casinos 题目连接: http://codeforces.com/contest/712/problem/E Description There are n casinos lined in a row. If Memory plays at casino i, he has probability pi to win and move to the casino on the right (i + 1) or exit the row (if i = n),…

题目链接: http://www.codeforces.com/contest/675/problem/E 题意: 对于第i个站,它与i+1到a[i]的站有路相连,先在求所有站点i到站点j的最短距离之和(1<=i<j<=n) 题解: 这种所有可能都算一遍就会爆的题目,有可能是可以转化为去求每个数对最后答案的贡献,用一些组合计数的方法一般就可以很快算出来. 这里用dp[i]表示第i个站点到后面的所有站的最短距离之和,明显,i+1到a[i]的站,一步就可以到,对于后面的那些点,贪心一下,一定…

D. Vika and Segments     Vika has an infinite sheet of squared paper. Initially all squares are white. She introduced a two-dimensional coordinate system on this sheet and drew n black horizontal and vertical segments parallel to the coordinate axes.…

题目链接: 题目 E. George and Cards time limit per test:2 seconds memory limit per test:256 megabytes 问题描述 George is a cat, so he loves playing very much. Vitaly put n cards in a row in front of George. Each card has one integer written on it. All cards had…

B. The Bakery time limit per test 2.5 seconds memory limit per test 256 megabytes input standard input output standard output Some time ago Slastyona the Sweetmaid decided to open her own bakery! She bought required ingredients and a wonder-oven whic…