D. The Fair Nut and the Best Path 题意:给出一张图 点有权值 边也要权值 从任意点出发到任意点结束 到每个点的时候都可以获得每个点的权值,而从边走的时候都要消耗改边的边权,如果当前值小于边的边权,就走不通,问从任意点出发到任意点结束的可以获得的最大权多少(其中到一个点结束的时候也能获得改点的值) 思路:一个很明显的树上dp的问题 \(dp[i]\)表示以i为起点的可以获得的最高的权值是多少 \(dp[i]=w[i]+max(son(dp[j]))\) 其中j为i…

D. The Fair Nut and the Best Path 题目链接:https://codeforces.com/contest/1084/problem/D 题意: 给出一棵树,走不重复的路径,每到一个结点加上其权值,经过一条边减去其权值,路径中途减去后不能出现负数,问怎么选择路径可以让最后得到的最大. 题解: 这题考虑用dp来做. 我们定义dp[u]为走到u点的最大值,注意这里的方向,是走到u点.题目中的意思是路径不能走回头路. 对于一个父节点u,那么我们可以根据走到其儿子结点的最…

E. The Fair Nut and Strings 题目链接:https://codeforces.com/contest/1084/problem/E 题意: 输入n,k,k代表一共有长度为n的多少个字符串.然后给出一个最小字符串s,最大字符串t,满足对于所有的k个字符串有s<=S<=t. 最后求满足条件的k个字符串(自己构造)的不同前缀数量的和. 题解: 这题很巧妙,设dp(i)表示长度为i的前缀的数量和,一开始有dp(1)=0. 后来随着长度的增加,我们每次可以在最后加一个a或者b,…

C. The Fair Nut and String 题目链接:https://codeforces.com/contest/1084/problem/C 题意: 给出一个字符串,找出都为a的子序列(比如ai,aj,ak)满足以下条件的个数: 1.子序列的索引单增(i<j<k): 2.在原字符串中,若ai=aj=ak=a,那么满足i<=k1<j,j<=k2<k 并且 ak1=ak2=b. 通俗点说,就是找这样的子序列个数:要么单个a,要么每个a之间都至少有一个b. 题解…

A. The Fair Nut and Elevator Solved. 签. #include <bits/stdc++.h> using namespace std; #define N 110 int n, a[N]; int main() { while (scanf("%d", &n) != EOF) { ; i <= n; ++i) scanf("%d", a + i); int res = 1e9; , tmp = ; x &…

毕竟是上紫之后的第一场div1,还是太菜了啊,看来我要滚回去打div2了. A. The Fair Nut and the Best Path 这题本来是傻逼贪心dfs,结果我越写越麻烦,然后就只有150了.. #include<cstdio> #include<cstring> #include<algorithm> #include<queue> #include<set> #include<map> #include<ve…

http://codeforces.com/contest/353/problem/C Codeforces Round #205 (Div. 2)C #include<stdio.h> ]; ]; ]; int Max(int a,int b){ if(a<b)return b; else return a; } int main(){ int n; while(scanf("%d",&n)!=EOF){ int i; dp[]=; ;i<=n;i++…

A. The Fair Nut and Elevator 好笨啊QAQ. 暴力枚举的题,连分类都不用. 从电梯初始位置到第一层.人到第一层.间隔的层数,往返路程. #include <bits/stdc++.h> using namespace std; int a[105]; int main() { int n; while(~scanf("%d",&n)) { int Min = 0x3ffffff; int ans = 0; for(int i = 1; i…

A. The Fair Nut and Elevator 题目链接:https://codeforces.com/contest/1084/problem/A 题意: 一栋房子有n层楼,同时有个电梯(每次只能载一个人),每层楼都有ai个人. 当电梯从x层到y层时,花费电力|x-y|. 现在要求当电梯位于哪一层时,所有人上下两次费用最少.电梯每次到一层后若电梯里面没人会回到我们选定的楼层. 题解: 枚举电梯位于的层数模拟一下就好了. 代码如下: #include <bits/stdc++.h>…

A. Scarborough Fair time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Are you going to Scarborough Fair? Parsley, sage, rosemary and thyme. Remember me to one who lives there. He once was th…

https://codeforces.com/contest/1084 A题 数据量很小,枚举就行 #include<iostream> #include<cstdio> #include<cstring> #include<map> #include<vector> #include<cmath> #include<algorithm> using namespace std; typedef long long ll;…

A. Scarborough Fair time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Are you going to Scarborough Fair? Parsley, sage, rosemary and thyme. Remember me to one who lives there. He once was th…

日常猝死. A:f[i]表示子树内包含根且可以继续向上延伸的路径的最大价值,统计答案考虑合并两条路径即可. #include<iostream> #include<cstdio> #include<cmath> #include<cstdlib> #include<cstring> #include<algorithm> using namespace std; #define ll long long #define N 30001…

题目大意: 给定一棵树 树上每个点有对应的点权 树上每条边有对应的边权 经过一个点可得到点权 经过一条边必须花费边权 即从u到v 最终得分=u的点权-u到v的边权+v的点权 求树上一条路径使得得分最大 看注释 #include <bits/stdc++.h> #define LL long long #define INf 0x3f3f3f3f using namespace std; ; bool vis[N]; LL w[N], ans; int n; ]; int head[N], to…

C. Kleofáš and the n-thlon Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/601/problem/C Description Kleofáš is participating in an n-thlon - a tournament consisting of n different competitions in n different disciplines (n…

  题目链接:http://codeforces.com/contest/766/problem/E Examples input 3 1 2 3 1 2 2 3 out 10 题意: 给你一棵n个点的树,每个点有点权,求所有不同的路径异或和的总和 题解: DP 任选一个root,设定dp[i][j][0]为以i为最高点的路径异或和中,二进制上第j为分别是0,1的数量 记录答案 #include<bits/stdc++.h> using namespace std; #pragma comme…

题目:http://codeforces.com/contest/1185/problem/G1 题意:给你n给选项,每个选项有个类型和价值,让你选择一个序列,价值和为m,要求连续的不能有两个相同的类型,相同的物]品不一样的顺序代表不同,问有多少个序列 思路:首先范围是15个,这里我们可以用状压来代表选择哪些物品,然后这里是说不能有连续相同的类型,这里我们贪心考虑不全,最开始我考虑的是组合数的插空法,当时 发现有很多细节,写不了,这样的话我们就只能改成dp, 我们设置dp[i][j]   代表i…

CodeForces - 811A A. Vladik and Courtesy time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output At regular competition Vladik and Valera won a and b candies respectively. Vladik offered 1 his can…

D. GukiZ and Binary Operations time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output We all know that GukiZ often plays with arrays. Now he is thinking about this problem: how many arrays a, of l…

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#include<bits/stdc++.h> #define int long long using namespace std; ; int a[maxn]; int dp[maxn]; int visit[maxn]; vector<int> vs[maxn]; map<pair<int,int>,int> mp; ; void dfs(int x) { visit[x]=; ; ; ;i<vs[x].size();i++) { int p=vs…

题目传送门 /* 题意:选择a[k]然后a[k]-1和a[k]+1的全部删除,得到点数a[k],问最大点数 DP:状态转移方程:dp[i] = max (dp[i-1], dp[i-2] + (ll) i * cnt[i]); 只和x-1,x-2有关,和顺序无关,x-1不取,x-2取那么累加相同的值,ans = dp[mx] */ #include <cstdio> #include <algorithm> #include <cstring> #include <…

Codeforces Round #485 (Div. 2) D. Fair 题目连接: http://codeforces.com/contest/987/problem/D Description Some company is going to hold a fair in Byteland. There are $n$ towns in Byteland and $m$ two-way roads between towns. Of course, you can reach any t…

Codeforces Round #436 (Div. 2) 敲出一身冷汗...感觉自己宛如智障:( codeforces 864 A. Fair Game[水] 题意:已知n为偶数,有n张卡片,每张卡片上都写有一个数,两个人每人选一个数,每人可以拿的卡片必须写有是自己选的数,问能否选择两个数使得两个人每人拿的卡片数一样多并且能拿光卡片.[就是看输入是不是只有两种数字] //:第一遍我看成字符串包含有选的数字也能拿,,这样写着居然过了..水题水题.. #include<cstdio> #inc…

Codeforces Round #272 (Div. 2) A. Dreamoon and Stairs time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Dreamoon wants to climb up a stair of n steps. He can climb 1 or 2 steps at each move.…

Codeforces Round #366 (Div. 2) A I hate that I love that I hate it水题 #I hate that I love that I hate it n = int(raw_input()) s = "" a = ["I hate that ","I love that ", "I hate it","I love it"] for i in ran…

Codeforces Round #354 (Div. 2) Problems     # Name     A Nicholas and Permutation standard input/output 1 s, 256 MB    x3384 B Pyramid of Glasses standard input/output 1 s, 256 MB    x1462 C Vasya and String standard input/output 1 s, 256 MB    x1393…

直达–>Codeforces Round #368 (Div. 2) A Brain’s Photos 给你一个NxM的矩阵,一个字母代表一种颜色,如果有”C”,”M”,”Y”三种中任意一种就输出”#Color”,如果只有”G”,”B”,”W”就输出”#Black&White”. #include <cstdio> #include <cstring> using namespace std; const int maxn = 200; const int INF =…

 cf之路,1,Codeforces Round #345 (Div. 2) ps:昨天第一次参加cf比赛,比赛之前为了熟悉下cf比赛题目的难度.所以做了round#345连试试水的深浅.....       其实这个应该是昨天就写完的,不过没时间了,就留到了今天.. 地址:http://codeforces.com/contest/651/problem/A A. Joysticks time limit per test 1 second memory limit per test 256…

Codeforces Round #279 (Div. 2) 做得我都变绿了! Problems     # Name     A Team Olympiad standard input/output 1 s, 256 MB  x2377 B Queue standard input/output 2 s, 256 MB  x1250 C Hacking Cypher standard input/output 1 s, 256 MB  x740 D Chocolate standard in…