Watchcow Time Limit: 3000MS Memory Limit: 65536K Total Submissions: 6172Accepted: 2663 Special Judge Description Bessie's been appointed the new watch-cow for the farm. Every night, it's her job to walk across the farm and make sure that no evildoers…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4392 题目大意: 一个图,要将每条边恰好遍历两遍,而且要以不同的方向,还要回到原点. dfs解法                   借鉴于->大佬博客 #include <iostream> #include <vector> #include <algorithm> using namespace std; #define arrsize 10001 int n,…

原题链接 类欧拉回路,要求每条边被正反各经过一次,且从\(1\)出发并回到\(1\). 只需每次搜索该点的边时,将该点的边对应的邻接表头及时修改为下一条即可,因为邻接表恰好储存了正反方向的边,所以及时更新表头就能保证每条边被正反各经过一次. #include<cstdio> using namespace std; const int N = 1e4 + 10; const int M = 5e4 + 10; int fi[N], di[M << 1], ne[M <<…

题目大意:给定一个 N 个点,M 条边的无向图,要求不重复地经过每条边两次,并且从 1 号节点出发最后回到 1 号节点,求一条路径. 题解:不重复地经过两次这个操作很容易地通过无向图的建边方式来实现,在欧拉回路的 dfs 过程中只需要每次将当前边标记访问过即可.同样,一个点所有边访问结束之后再入栈,最后倒序输出结果即是一组答案. 代码如下 #include <cstdio> #include <utility> #include <cstring> #include &…

题目链接:http://poj.org/problem?id=2230 题目: 题意:给你m条路径,求一条路径使得从1出发最后回到1,并满足每条路径都恰好被沿着正反两个方向经过一次. 思路:由于可以回到起点,并且题目保证有解,所以本题是欧拉回路.输出路径有两种方法,一种是递归实现,一种是用栈处理,不过两种速度差了1s,不知道是不是我递归没处理好~ 代码实现如下(第一种为栈输出路径,对应797ms,第二种为递归,对应1782ms): #include <set> #include <map…

http://poj.org/problem?id=2230 Description Bessie's been appointed the new watch-cow for the farm. Every night, it's her job to walk across the farm and make sure that no evildoers are doing any evil. She begins at the barn, makes her patrol, and the…

主题链接: http://poj.org/problem? id=2230 Watchcow Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 6055   Accepted: 2610   Special Judge Description Bessie's been appointed the new watch-cow for the farm. Every night, it's her job to walk ac…

Watchcow Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 6477   Accepted: 2823   Special Judge Description Bessie's been appointed the new watch-cow for the farm. Every night, it's her job to walk across the farm and make sure that no ev…

Bessie's been appointed the new watch-cow for the farm. Every night, it's her job to walk across the farm and make sure that no evildoers are doing any evil. She begins at the barn, makes her patrol, and then returns to the barn when she's done. If s…

Watchcow Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 5258   Accepted: 2206   Special Judge Description Bessie's been appointed the new watch-cow for the farm. Every night, it's her job to walk across the farm and make sure that no ev…