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…

D. Valid Sets   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 consisting of n nodes. Each node i has a value ai associated with it. We call a set S of tree nodes valid …

D. Valid Sets Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/486/problem/D Description 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 consist…

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…

#include<bits/stdc++.h>using namespace std;int a[5007];int dp[5007][5007];int main(){    int n; scanf("%d",&n);    for(int i=1;i<=n;i++)        scanf("%d",&a[i]);    n=unique(a+1,a+1+n)-a-1;    for(int i=n;i>=1;i--)…

Codeforces Round #277 (Div. 2) A. Calculating Function time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output For a positive integer n let's define a function f: f(n) =  - 1 + 2 - 3 + .. + ( - 1)n…

门户:Codeforces Round #277 (Div. 2) 486A. Calculating Function 裸公式= = #include <cstdio> #include <cstring> #include <algorithm> using namespace std ; typedef long long LL ; LL n ; int main () { while ( ~scanf ( "%I64d" , &n )…

题目传送门 /* 贪心+构造:因为是对称的,可以全都左一半考虑,过程很简单,但是能想到就很难了 */ /************************************************ Author :Running_Time Created Time :2015-8-3 9:14:02 File Name :B.cpp *************************************************/ #include <cstdio> #include &…

Problem  Codeforces Round #556 (Div. 2) - D. Three Religions Time Limit: 1000 mSec Problem Description Input Output Sample Input 51 2 1 2 1 Sample Output 1 1 1 2 2 题解:这个题有做慢了,这种题做慢了和没做出来区别不大... 读题的时候脑子里还意识到素数除了2都是奇数,读完之后就脑子里就只剩欧拉筛了,贪心地构造使得前缀和是连续的素数,那…

A. Calculating Function 水题,分奇数偶数处理一下就好了 #include<stdio.h> #include<iostream> using namespace std; int main() { long long n;scanf("%lld",&n); ==) printf("%lld\n",(n-1LL)/2LL - n); else printf("%lld\n",n/2LL); }…