C. Robbers' watch time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Robbers, who attacked the Gerda's cab, are very successful in covering from the kingdom police. To make the goal of catchi…

A. Robbers' watch 题目连接: http://www.codeforces.com/contest/685/problem/A Description Robbers, who attacked the Gerda's cab, are very successful in covering from the kingdom police. To make the goal of catching them even harder, they use their own watc…

C. Robbers' watch time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Robbers, who attacked the Gerda's cab, are very successful in covering from the kingdom police. To make the goal of catchi…

题目链接:http://codeforces.com/problemset/problem/686/C 给你n和m,问你有多少对(a, b) 满足0<=a <n 且 0 <=b < m 且a的7进制和n-1的7进制位数相同 且b的7进制和m-1的7进制位数相同,还有a和b的7进制上的每位上的数各不相同. 看懂题目,就很简单了,先判断a和b的7进制位数是否超过7,不超过的话就dfs暴力枚举计算就可以了. //#pragma comment(linker, "/STACK:1…

题目链接:http://codeforces.com/contest/686/problem/C题目大意:给你两个十进制的数n和m,选一个范围在[0,n)的整数a,选一个范围在[0,m)的整数b,要求a的7进制表示和b的7进制表示中的每一位都不重复.其中,a的7进制位数和n-1的7进制位数相同,b的位数和m-1的位数相同.比如,当n=2,m=3时,a和b的其进制表示的所有集合是:a=0, b=1 a=0, b=2 a=1, b=0a=1, b=2 解法:这套题目可以用dfs做.我们开一个数组f[…

A http://codeforces.com/contest/685/standings 题意:给你n和m,找出(a,b)的对数,其中a满足要求:0<=a<n,a的7进制的位数和n-1的7进制的位数相同,b满足要求:0<=b<m,b的7进制的位数和m-1的7进制的位数相同,且a和b的7进制下的位上的数都不相同 思路:如果a b的位数和大于7显然会有重复,缩小范围以后,可以根据题意暴力枚举 // #pragma comment(linker, "/STACK:102400…

B. Kay and Snowflake 题目连接: http://www.codeforces.com/contest/685/problem/B Description After the piece of a devilish mirror hit the Kay's eye, he is no longer interested in the beauty of the roses. Now he likes to watch snowflakes. Once upon a time,…

B. Little Robber Girl's Zoo 题目连接: http://www.codeforces.com/contest/686/problem/B Description Little Robber Girl likes to scare animals in her zoo for fun. She decided to arrange the animals in a row in the order of non-decreasing height. However, th…

A. Free Ice Cream 题目连接: http://www.codeforces.com/contest/686/problem/A Description After their adventure with the magic mirror Kay and Gerda have returned home and sometimes give free ice cream to kids in the summer. At the start of the day they hav…

C. Robbers' watch time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Robbers, who attacked the Gerda's cab, are very successful in covering from the kingdom police. To make the goal of catchi…

A:= v = B:^ w ^ C:一天n个小时,一个小时m分(n,m十进制),一个手表有两部分,左边表示时,右边表示分,但都是7进制,而且手表上最多只能有7个数字且数字不能重复,现在要你算出能正确表示出多少个时间(不够位需要补0).因为进制只有7,所以可以枚举所有的7进制数,然后再切成7组,分为左边和右边,判断是否符合n,m条件,计数即可.O(7*7^7) D:给你一个n个节点的树,有q个询问(n,q<=300000),每次询问一个x,问以x为顶点的子树中,删除哪一个点后使得这个子树剩下的联通…

D. Kay and Snowflake     After the piece of a devilish mirror hit the Kay's eye, he is no longer interested in the beauty of the roses. Now he likes to watch snowflakes. Once upon a time, he found a huge snowflake that has a form of the tree (connect…

题目链接: 题目 D. Kay and Snowflake time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output 问题描述 After the piece of a devilish mirror hit the Kay's eye, he is no longer interested in the beauty of the r…

D - Kay and Snowflake 题目大意:给你一棵数q个询问,每个询问给你一个顶点编号,要你求以这个点为根的子树的重心是哪个节点. 定义:一棵树的顶点数为n,将重心去掉了以后所有子树的顶点的个数的两倍不会超过n. 性质 1 :树中所有点到某个点的距离和中,到重心的距离和是最小的,如果有两个距离和,他们的距离和一样. 性质 2 :把两棵树通过某一点相连得到一颗新的树,新的树的重心必然在连接原来两棵树重心的路径上. 性质 3 :一棵树添加或者删除一个节点,树的重心最多只移动一条边的位置.…

B. Little Robber Girl's Zoo time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Little Robber Girl likes to scare animals in her zoo for fun. She decided to arrange the animals in a row in the…

A. Free Ice Cream time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output After their adventure with the magic mirror Kay and Gerda have returned home and sometimes give free ice cream to kids in…

原博主:https://blog.csdn.net/amovement/article/details/80358962 B. Bus of Characters time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output In the Bus of Characters there are nn rows of seat, each h…

题意:有一长度为\(n\)的字符串,要求得到\(k\)不同的它的子序列(可以是空串),每个子序列有\(|n|-|t|\)的贡献,求合法情况下的最小贡献. 题解:直接撸个爆搜找出所有子序列然后放到set里面搞一下就好了. 代码: int n,k; string str; set<string> s; queue<string> q; void bfs(){ s.insert(str); q.push(str); while(!q.empty()){ string cur=q.fron…

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…

题目传送门 /* 题意:从前面找一个数字和末尾数字调换使得变成偶数且为最大 贪心:考虑两种情况:1. 有偶数且比末尾数字大(flag标记):2. 有偶数但都比末尾数字小(x位置标记) 仿照别人写的,再看自己的代码发现有清晰的思维是多重要 */ #include <cstdio> #include <iostream> #include <algorithm> #include <cmath> #include <cstring> #include…

#include <iostream> #include <string> using namespace std; int main(){ int n; cin >> n; string str; cin >> str; , x = ; ; i < n ; ++ i){ if(str[i] == 'B') cnt+=(x << i); } cout<<cnt<<endl; }   Codeforces Round…