B. Problems for Round 题目连接: http://www.codeforces.com/contest/673/problem/B Description There are n problems prepared for the next Codeforces round. They are arranged in ascending order by their difficulty, and no two problems have the same difficult…

B. Problems for Round time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output There are n problems prepared for the next Codeforces round. They are arranged in ascending order by their difficulty,…

C. Bear and Forgotten Tree 3 time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A tree is a connected undirected graph consisting of n vertices and n  -  1 edges. Vertices are numbered 1 thro…

连接在这里,->点击<- A. Bear and Game time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Bear Limak likes watching sports on TV. He is going to watch a game today. The game lasts 90 minutes and ther…

A - Little Artem and Presents (div2) 1 2 1 2这样加就可以了 #include <bits/stdc++.h> typedef long long ll; const int N = 1e5 + 5; int main() { int n; scanf ("%d", &n); int ans = n / 3 * 2; if (n % 3) { ans++; } printf ("%d\n", ans);…

A.暴力枚举,注意游戏最长为90分钟 B.暴力,c[l]++,c[r]--,记录中间有多长的段是大小为n的,注意特判m=0的情况 C.暴力枚举,我居然一开始没想出来!我一直以为每次都要统计最大的,就要O(N^3).实际上只要判断最大的那个. D.构造,在除了a,b,c,d之外的点构造一条链,只需要n+1条边就可以了.n=4的时候特判.…

题目链接: http://codeforces.com/contest/673/problem/D 题意: 给四个不同点a,b,c,d,求是否能构造出两条哈密顿通路,一条a到b,一条c到d. 题解: 构造法,看例子: input: 5 6 5 2 4 1 output: 5 4 3 1 2 4 5 3 2 1 所以只要满足k>=n+1,就可以构造出来答案. #include<iostream> #include<cstring> #include<cstdio>…

题目链接: http://codeforces.com/contest/673/problem/C 题解: 枚举所有的区间,维护一下每种颜色出现的次数,记录一下出现最多且最小的就可以了. 暴力n*n. #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<vector> using namespace std; ; const int…

题目链接: http://codeforces.com/contest/669/problem/D 题意: 给你一个初始序列:1,2,3,...,n. 现在有两种操作: 1.循环左移,循环右移. 2.1,2位置交换,3,4位置交换,...,n-1,n位置交换 现在问执行了q次操作之后序列是什么,每次操作可以是两种操作的任意一种 题解: 我们把数列按位置的奇偶分为两堆,无论哪种操作,始终都还是这两堆,最多就是整堆的对换和一个堆内部的偏移. 所以我们只要记录第一个位置和第二个位置的数的变化(相当于每…

D. Bear and Two Paths 题目连接: http://www.codeforces.com/contest/673/problem/D Description Bearland has n cities, numbered 1 through n. Cities are connected via bidirectional roads. Each road connects two distinct cities. No two roads connect the same p…