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…

Watchcow Time Limit: 3000MS Memory Limit: 65536K Total Submissions: 9974 Accepted: 4307 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 evildoer…

转自:http://blog.csdn.net/shahdza/article/details/7779385 欧拉回路[HDU]1878 欧拉回路 判断3018 Ant Trip 一笔画问题1116 Play on Words2894 DeBruijin 兹鼓欧拉回路1956 Sightseeing tour 混合欧拉3472 HS BDC 混合欧拉=========================================================================…

转自——http://blog.csdn.net/qwe20060514/article/details/8112550 =============================以下是最小生成树+并查集======================================[HDU]1213   How Many Tables   基础并查集★1272   小希的迷宫   基础并查集★1325&&poj1308  Is It A Tree?   基础并查集★1856   More i…

=============================以下是最小生成树+并查集====================================== [HDU] How Many Tables 基础并查集★ 小希的迷宫 基础并查集★ &&poj1308 Is It A Tree? 基础并查集★ More is better 基础并查集★ Constructing Roads 基础最小生成树★ 畅通工程 基础并查集★ 还是畅通工程 基础最小生成树★ 畅通工程 基础最小生成树★ 畅通…

POJ图论分类[转] 一个很不错的图论分类,非常感谢原版的作者!!!在这里分享给大家,爱好图论的ACMer不寂寞了... (很抱歉没有找到此题集整理的原创作者,感谢知情的朋友给个原创链接) POJ:http://poj.org/ 1062* 昂贵的聘礼 枚举等级限制+dijkstra 1087* A Plug for UNIX 2分匹配 1094 Sorting It All Out floyd 或 拓扑 1112* Team Them Up! 2分图染色+DP 1125 Stockbroker…

=============================以下是最小生成树+并查集====================================== [HDU] 1213 How Many Tables 基础并查集★ 1272 小希的迷宫 基础并查集★ 1325&&poj1308 Is It A Tree? 基础并查集★ 1856 More is better 基础并查集★ 1102 Constructing Roads 基础最小生成树★ 1232 畅通工程 基础并查集★ 123…

=============================以下是最小生成树+并查集====================================== [HDU] 1213 How Many Tables 基础并查集★ 1272 小希的迷宫 基础并查集★ 1325&&poj1308 Is It A Tree? 基础并查集★ 1856 More is better 基础并查集★ 1102 Constructing Roads 基础最小生成树★ 1232 畅通工程 基础并查集★ 123…

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…

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 then returns to the barn when she'…

Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 8109   Accepted: 3551   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 a…

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…

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…

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…

关键是每条边必须走两遍,重复建边即可,因为确定了必然存在 Euler Circuit ,所以所有判断条件都不需要了. 注意:我是2500ms跑过的,鉴于这道题ac的code奇短,速度奇快,考虑解法应该不唯一. #include<cstdio> #include<cstring> #include<vector> #include<stack> #include<algorithm> #define rep(i,a,b) for(int i=a;i…

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,…

题目链接:http://poj.org/problem?id=2230 题目大意:给你n个点m条边,Bessie希望能走过每条边两次,且两次的方向相反,让你输出以点的形式输出路径. 解题思路:其实就是输出有向图的欧拉路,只是让你以点的形式输出.建图的时候,输入a,b直接建立(a,b)和(b,a)正反两条边,然后dfs递归遍历即可.注意输出点的位置:在边遍历完之后输出,原理暂时还没搞懂. 代码: #include<iostream> #include<cstdio> #include…

http://poj.org/problem?id=2230 题意:给出n个field及m个连接field的边,然后要求遍历每条边仅且2次,求出一条路径来. #include <stdio.h> #include <string.h> ; *; int head[maxn],vis[maxm]; struct node { int u; int v; int next; } edge[maxm]; int n,m,cnt; void init() { memset(head,-,s…

Watchcow Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 7512   Accepted: 3290   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…

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: 65536KB This problem will be judged on PKU. Original ID: 223064-bit integer IO format: %lld      Java class name: Main   Bessie's been appointed the new watch-cow for the farm. Every night, it's her job to wa…

//网络流判定混合图欧拉回路 //通过网络流使得各点的出入度相同则possible,否则impossible //残留网络的权值为可改变方向的次数,即n个双向边则有n次 //Time:157Ms Memory:348K #include <iostream> #include<cstring> #include<cstdio> #include<algorithm> #include<queue> using namespace std; #de…

注意:找出一条欧拉回路,与判定这个图能不能一笔联通...是不同的概念 c++奇怪的编译规则...生不如死啊... string怎么用啊...cincout来救? 可以直接.length()我也是长见识了... CE怎么办啊...g++来救? #include<cstdio> #include<iostream> #include<cstring> #include<cmath> #include<algorithm> #define N 2020…

 FZU 2112 Tickets Time Limit:3000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Practice Description You have won a collection of tickets on luxury cruisers. Each ticket can be used only once, but can be used in either direction betwee…

有n个珠子,每颗珠子有左右两边两种颜色,颜色有1~50种,问你能不能把这些珠子按照相接的地方颜色相同串成一个环. 可以认为有50个点,用n条边它们相连,问你能不能找出包含所有边的欧拉回路 首先判断是否在一个联通分量中,在判断是否存在欧拉回路,最后输出欧拉回路. #include <stdio.h> #include <string.h> ; <<; int mx,mn,p[maxn],d[maxn],G[maxn][maxn]; int find(int x) { re…

题意:一张混合图,判断是否存在欧拉回路. 分析参考: 混合图(既有有向边又有无向边的图)中欧拉环.欧拉路径的判定需要借助网络流! (1)欧拉环的判定:一开始当然是判断原图的基图是否连通,若不连通则一定不存在欧拉环或欧拉路径(不考虑度数为0的点). 其实,难点在于图中的无向边,需要对所有的无向边定向(指定一个方向,使之变为有向边),使整个图变成一个有向欧拉图(或有向半欧拉图).若存在一个定向满足此条件,则原图是欧拉图(或半欧拉图)否则不是.关键就是如何定向? 首先给原图中的每条无向边随便指定一个方…

Problem One-Way Reform 题目大意 给一张n个点,m条边的无向图,要求给每条边定一个方向,使得最多的点入度等于出度,要求输出方案. 解题分析 最多点的数量就是入度为偶数的点. 将入度为奇数的点每两个组成一队,连一条无向边,之后求出欧拉回路即可. 参考程序 #include <map> #include <set> #include <stack> #include <queue> #include <cmath> #inclu…

https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=3270 2017年的第一题. 题意:给出必须要经过的边,找一条经过所有边的最短道路. 一开始一点想法都没有,后来网上看了下才明白是要用dfs和欧拉回路来做的. 欧拉回路是这样说的:如果一个无向图是连通的,且最多只有两个奇点,则一定存在欧拉道路.如果有两个奇点,则必须从其中一个奇点出发,另一个…

题目:这里 题意:有一种由彩色珠子连接而成的项链,每个珠子两半由不同颜色(由1到50的数字表示颜色)组成,相邻的两个珠子在接触的地方颜色相同,现在有一些零碎的珠子,确认它是否能 复原成完整的项链. 把每种颜色看成一个结点,每个珠子的两半连成一条有向边,就成了判断一个欧拉回路了,而输出回路路线可以用dfs,逆序输出,因为顺序输出的时候,由于可能会有一个结点上多 条边的情况,dfs的时候可能一开始会找到错误的路线再回溯回去,顺序输出就把这段错误的路线也输出了. #include<cstdio> #…

/* 题意:将两端涂有颜色的木棒连在一起,并且连接处的颜色相同! 思路:将每一个单词看成一个节点,建立节点之间的无向图!判断是否是欧拉回路或者是欧拉路 并查集判通 + 奇度节点个数等于2或者0 */ #include<cstring> #include<cstdio> #include<algorithm> #define N 2500005*2 using namespace std; int f[N]; ]; int rank[N]; int deg[N]; int…