题目传送门 /* 题意:求一个点为根节点,使得到其他所有点的距离最短,是有向边,反向的距离+1 树形DP:首先假设1为根节点,自下而上计算dp[1](根节点到其他点的距离),然后再从1开始,自上而下计算dp[v], 此时可以从上个节点的信息递推出来 */ #include <cstdio> #include <cstring> #include <cmath> #include <vector> using namespace std; ; const in…

D. Choosing Capital for Treeland time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output The country Treeland consists of n cities, some pairs of them are connected with unidirectional roads. Over…

time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output The country Treeland consists of n cities, some pairs of them are connected with unidirectional roads. Overall there are n - 1 roads in the…

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题目传送门 /* 构造:从大到小构造,每一次都把最后不是9的变为9,p - p MOD 10^k - 1,直到小于最小值. 另外,最多len-1次循环 */ #include <cstdio> #include <algorithm> #include <cstring> #include <cmath> using namespace std; typedef long long ll; ; const int INF = 0x3f3f3f3f; int…

题目传送门 /* 贪心:当m == 2时,结果肯定是ABABAB或BABABA,取最小改变量:当m > 2时,当与前一个相等时, 改变一个字母 同时不和下一个相等就是最优的解法 */ #include <cstdio> #include <cstring> #include <algorithm> using namespace std; ; const int INF = 0x3f3f3f3f; char s[MAXN]; int main(void) { //…

A. k-String 统计每个字母出现次数即可. B. Special Offer! Super Price 999 Bourles! 枚举末尾有几个9,注意不要爆掉\(long\ long\)的范围. C. Color Stripe 当\(k\gt 2\)时,若\(s_i==s_{i-1}\),那么枚举新的字母使得\(s_i \ne s_{i-1},s_i \ne s_{i+1}\). 当\(k\gt 2\)时,则需要枚举首位是\(A\)是\(B\).在\(AAB\)这种情况下,\(k\gt…

题目链接:https://codeforces.com/contest/1379/problem/C 题意 有 $m$ 种花,每种花数量无限,第一次购买一种花收益为 $a_i$,之后每一次购买收益为 $b_i$,问买 $n$ 朵花的最大收益为多少. 题解 感觉是个 $dp$,实际上是个贪心. 一定是一种花买了很多,其他花不买或只买一次,当其他花第一次购买的收益 $a_j$ 大于要买较多花的 $b_i$ 时,可以将一个 $b_i$ 换为其他花的 $a_j$ . 枚举哪种花买的较多,然后在 $a$…

给定n k以及n个人已参加的比赛数,让你判断最少还能参加k次比赛的队伍数,每对3人,每个人最多参加5次比赛 #include <iostream> using namespace std; int main(){ ; cin >> n >> k; ; i < n; ++ i){ int a; cin >> a; ) cnt ++; } cout<<cnt/<<endl; }…

E. Parking Lot time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A parking lot in the City consists of n parking spaces, standing in a line. The parking spaces are numbered from 1 to n from…

k-String time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A string is called a k-string if it can be represented as k concatenated copies of some string. For example, the string "aabaabaaba…

C. Riding in a Lift Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/480/problem/C Description Imagine that you are in a building that has exactly n floors. You can move between the floors in a lift. Let's number the floors f…

D. Babaei and Birthday Cake 题目连接: http://www.codeforces.com/contest/629/problem/D Description As you know, every birthday party has a cake! This time, Babaei is going to prepare the very special birthday party's cake. Simple cake is a cylinder of som…

http://codeforces.com/contest/510/status/B 题目大意 给一个n*m  找有没有相同字母连起来的矩形串 第一种并查集 瞎搞一下 第一次的时候把val开成字符串了 所以wa 改了AC #include<cstdio> #include<map> //#include<bits/stdc++.h> #include<vector> #include<stack> #include<iostream>…

D. Little Pony and Harmony Chest   Princess Twilight went to Celestia and Luna's old castle to research the chest from the Elements of Harmony. A sequence of positive integers bi is harmony if and only if for every two elements of the sequence their…

A. Alex and broken contest time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output One day Alex was creating a contest about his friends, but accidentally deleted it. Fortunately, all the problems…

A. Combination Lock time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Scrooge McDuck keeps his most treasured savings in a home safe with a combination lock. Each time he wants to put there…

A. One-dimensional Japanese Crossword time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Recently Adaltik discovered japanese crosswords. Japanese crossword is a picture, represented as a tabl…

A. Laptops time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output One day Dima and Alex had an argument about the price and quality of laptops. Dima thinks that the more expensive a laptop is, the…

今天老师(orz sansirowaltz)让我们做了很久之前的一场Codeforces Round #257 (Div. 1),这里给出A~C的题解,对应DIV2的C~E. A.Jzzhu and Chocolate time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Jzzhu has a big rectangular cho…

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…

Codeforces Round #262 (Div. 2) 1003 C. Present time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Little beaver is a beginner programmer, so informatics is his favorite subject. Soon his info…

Codeforces Round #262 (Div. 2) 1004 D. Little Victor and Set time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Little Victor adores the sets theory. Let us remind you that a set is a group of…

A: 题目大意: 在一个multiset中要求支持3种操作: 1.增加一个数 2.删去一个数 3.给出一个01序列,问multiset中有多少这样的数,把它的十进制表示中的奇数改成1,偶数改成0后和给出的01序列相等(比较时如果长度不等各自用0补齐) 题解: 1.我的做法是用Trie数来存储,先将所有数用0补齐成长度为18位,然后就是Trie的操作了. 2.官方题解中更好的做法是,直接将每个数的十进制表示中的奇数改成1,偶数改成0,比如12345,然后把它看成二进制数10101,还原成十进制是2…

CF469 Codeforces Round #268 (Div. 2) http://codeforces.com/contest/469 开学了,时间少,水题就不写题解了,不水的题也不写这么详细了. A 水题 //#pragma comment(linker, "/STACK:102400000,102400000") #include<cstdio> #include<cmath> #include<iostream> #include<…

题目传送门 /* 贪心 + 模拟:首先,如果蜡烛的燃烧时间小于最少需要点燃的蜡烛数一定是-1(蜡烛是1秒点一支), num[g[i]]记录每个鬼访问时已点燃的蜡烛数,若不够,tmp为还需要的蜡烛数, 然后接下来的t秒需要的蜡烛都燃烧着,超过t秒,每减少一秒灭一支蜡烛,好!!! 详细解释:http://blog.csdn.net/kalilili/article/details/43412385 */ #include <cstdio> #include <algorithm> #i…