Codeforces Round #379 (Div. 2) E. Anton and Tree
题意：给一颗树 每个节点有黑白2色可以使一个色块同事变色，问最少的变色次数。思路：先缩点 把一样颜色的相邻点 缩成一个然后新的树 刚好每一层是一个颜色。最后的答案就是树的直径/2不过我用的树上的dp，强行求了以每个点为根时树的深度答案就是最小的深度-1具体见代码：const int maxn = ...
Codeforces Round #225 (Div. 1) C. Propagating tree dfs序+树状数组
C. Propagating treeTime Limit: 20 SecMemory Limit: 256 MB题目连接http://codeforces.com/contest/383/problem/CDescriptionIahub likes trees very much. Recent...
CodeForces - 803F： Coprime Subsequences（莫比乌斯&容斥）
Let's call a non-empty sequence of positive integers a1, a2... ak coprime if the greatest common divisor of all elements of this sequence is equal to ...
Codeforces Round #260 (Div. 1) D. Serega and Fun 分块
D. Serega and FunTime Limit: 20 SecMemory Limit: 256 MB题目连接http://codeforces.com/contest/455/problem/DDescriptionSerega loves fun. However, everyone h...
Codeforces Round #260 (Div. 2) C
DescriptionAlex doesn't like boredom. That's why whenever he gets bored, he comes up with games. One long winter evening he came up with a game and de...
Codeforces Round #260 (Div. 1) 455 A. Boredom （DP）
题目链接：http://codeforces.com/problemset/problem/455/AA. Boredomtime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputsta...
Codeforces Round #260 (Div. 1) C. Civilization 并查集，直径
C. CivilizationTime Limit: 20 SecMemory Limit: 256 MB题目连接http://codeforces.com/contest/455/problem/CDescriptionAndrew plays a game called "Civilizatio...
Codeforces Round #260 (Div. 1) A - Boredom DP
A. BoredomTime Limit: 20 SecMemory Limit: 256 MB题目连接http://codeforces.com/contest/455/problem/ADescriptionAlex doesn't like boredom. That's why whenev...
Codeforces Round #260 (Div. 2)AB
http://codeforces.com/contest/456/problem/AA. Laptopstime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard ou...
Codeforces Round #364 (Div. 2) C. They Are Everywhere 尺取法
C. They Are Everywheretime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputSergei B., the young coach...
CodeForces 125E MST Company
E. MST Companytime limit per test 8 secondsmemory limit per test 256 megabytesinput standard inputoutput standard outputThe MST (Meaningless State Tea...
CODEFORCES #272 DIV2[为填完]
#272是自己打的第一场cf,感觉这一套质量挺棒的，不像后两场略水//先附上A,B,C的题解，因为离noip只剩下一点时间了，所以之后不一定还刷cf，暂且就先放上前三题好了A题目大意忘了。懒得看，反正很水。B组合数学：题目大意：给你两个字符串；s1,s2其中s2字符串可能含有未知的字符，对于未知的字...
CodeForces - 1249E 楼梯和电梯
题意：第一行输入n和c,表示有n层楼，电梯来到需要时间c输入两行数，每行n-1个，表示从一楼到二楼，二楼到三楼.....n-1楼到n楼，a[ ] 走楼梯和 b[ ] 乘电梯花费的时间思路：动态规划，考虑几种状态，假设当前在i-1层，想要去i层，有两种方法，乘电梯，走楼梯。i-1层要考虑由什么状态到i...
Codeforces1102F Elongated Matrix 【状压DP】
题目分析：这题瞎搞一个哈密尔顿路，对于起点不同的分开跑就可以过了。$O(n^3*2^n)$ #include<bits/stdc++.h> using namespace std; const int maxn = ; const int maxm = ; int n,m; int a[...
Codeforces Round 924 (Div. 2) ---- F. Digital Patterns ---- 题解
F. Digital Patterns： 题目描述： 思路解析： 要求在一个方块中，任意相邻的方块中他的透明度系数不能相同，这样的方块称为趣味性方块，问这样的方块有多少种。 那么我们可以相当，假设 a1 == a2, 那么每一列的第一行元素都等于第二行元素。 假设b1==b2，那么每一行的第...
codeforces 192a
link: http://codeforces.com/contest/330/problem/Abrute force. /* ID: zypz4571 LANG: C++ TASK: 191a.cpp */ #include <cstdio> #include <cstdli...
Codeforces Round 931 (Div. 2)
Codeforces Round 931 (Div. 2) Codeforces Round 931 (Div. 2) A. Too Min Too Max 题意： 从n个元素中选取四个元素进行按任意顺序排列，进行以下计算，求出可能的最大值 ...
Codeforces Round #250 (Div. 1) D. The Child and Sequence 线段树 区间取摸
D. The Child and SequenceTime Limit: 20 SecMemory Limit: 256 MB题目连接http://codeforces.com/contest/438/problem/DDescriptionAt the children's day, the ch...
Codeforces Round #200 (Div. 1) C. Read Time 二分
C. Read TimeTime Limit: 1 SecMemory Limit: 256 MB题目连接http://codeforces.com/contest/343/problem/CDescriptionMad scientist Mike does not use slow hard d...
Codeforces Round #360 (Div. 2) C D E
每次AB秒出 到了C难度陡然上升...翻译都弄不懂...C 给出一张图 找出两个点的覆盖集(覆盖集是指这图中每条边都有至少一个点在这个点集里面) 并且两个点集没有交集 英文很难看懂...就是二分图的判定 看看这张图是不是二分图 输出两边的点 不是二分图输出-1坑点是这是special judge 但...