D. Subway A subway scheme, classic for all Berland cities is represented by a set of n stations connected by n passages, each of which connects exactly two stations and does not pass through any others. Besides, in the classic scheme one can get from…

题目链接:http://codeforces.com/problemset/problem/131/D 思路: 题目的意思是说给定一个无向图,求图中的顶点到环上顶点的最短距离(有且仅有一个环,并且环上顶点的距离不计). 一开始我是直接用Tarjan求的无向图的双连通分量,然后标记连通分量上的点(如果某一个连通分量上的顶点的个数大于1,那么就是环了,其余的都只有一个点),然后即使重新建图,spfa求最短路径. #include <iostream> #include <cstdio>…

D. Subway   A subway scheme, classic for all Berland cities is represented by a set of n stations connected by n passages, each of which connects exactly two stations and does not pass through any others. Besides, in the classic scheme one can get fr…

题目链接:http://www.codeforces.com/problemset/problem/131/A题意:字符串大小写转换.C++代码: #include <cstdio> #include <cstring> ]; bool islow(char c) { return c >= 'a' && c <= 'z'; } char up(char c) { ; } char low(char c) { ; } bool check() { cha…

C. The World is a Theatre There are n boys and m girls attending a theatre club. To set a play "The Big Bang Theory", they need to choose a group containing exactly t actors containing no less than 4 boys and no less than one girl. How many ways…

C. The World is a Theatre time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output There are n boys and m girls attending a theatre club. To set a play "The Big Bang Theory", they need to choo…

C. Statues time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output In this task Anna and Maria play a game with a very unpleasant rival. Anna and Maria are in the opposite squares of a chessboard…

Codeforces Beta Round #80 (Div. 2 Only) A Blackjack1 题意 一共52张扑克,A代表1或者11,2-10表示自己的数字,其他都表示10 现在你已经有一个queen了,问你有多少种方案,能够得到n点 题解 其实只用考虑三种情况,都考虑一下就好了,实在不行就暴力枚举-- 代码 #include<bits/stdc++.h> using namespace std; int n; int main() { scanf("%d",&…

Codeforces Beta Round #83 (Div. 1 Only) A. Dorm Water Supply 题意 给你一个n点m边的图,保证每个点的入度和出度最多为1 如果这个点入度为0,那么这个点就是水龙头点. 如果这个点的出度为0,那么这个点就是储存点. 现在让你把所有水龙头到储存点的路径都输出出来,且输出这条路径的边权最小值 题解 显然是个仙人掌图,所以直接XJB暴力就好了 代码 #include<bits/stdc++.h> using namespace std; co…

Codeforces Beta Round #79 (Div. 2 Only) http://codeforces.com/contest/102 A #include<bits/stdc++.h> using namespace std; #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define sqr(x) ((x)*(x)) #define pb push_back #define eb empla…