Get Luffy Out Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 8851   Accepted: 3441 Description Ratish is a young man who always dreams of being a hero. One day his friend Luffy was caught by Pirate Arlong. Ratish set off at once to Arlo…

HDU 1816, POJ 2723 Get Luffy Out pid=1816" target="_blank" style="">题目链接 题意:N串钥匙.每串2把,仅仅能选一把.然后有n个大门,每一个门有两个锁,开了一个就能通过,问选一些钥匙,最多能通过多少个门 思路:二分通过个数.然后对于钥匙建边至少一个不选,门建边至少一个选,然后2-sat搞一下就可以. 一開始是按每串钥匙为1个结点,但是后面发现数据有可能一把钥匙,出如今不同串(真是不合…

题目链接 给n个钥匙对, 每个钥匙对里有两个钥匙, 并且只能选择一个. 有m扇门, 每个门上有两个锁, 只要打开其中一个就可以通往下一扇门. 问你最多可以打开多少个门. 对于每个钥匙对, 如果选择了其中一个钥匙, 那么另一个就不能选. 所以加边(a, b'), (b, a'). 对于每个门, 如果不打开其中一个锁, 那么另一个锁就一定要打开. 所以加边(a', b), (b', a). 然后二分判断就可以了. #include <iostream> #include <vector>…

Description Ratish is a young man who always dreams of being a hero. One day his friend Luffy was caught by Pirate Arlong. Ratish set off at once to Arlong's island. When he got there, he found the secret place where his friend was kept, but he could…

Description Ratish is a young man who always dreams of being a hero. One day his friend Luffy was caught by Pirate Arlong. Ratish set off at once to Arlong's island. When he got there, he found the secret place where his friend was kept, but he could…

Get Luffy Out Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 8211   Accepted: 3162 Description Ratish is a young man who always dreams of being a hero. One day his friend Luffy was caught by Pirate Arlong. Ratish set off at once to Arlo…

两个钥匙a,b是一对,隐含矛盾a->!b.b->!a 一个门上的两个钥匙a,b,隐含矛盾!a->b,!b->a(看数据不大,我是直接枚举水的,要打开当前门,没选a的话就一定要选b打开.没选b的话,就一定要选a打开) #include<iostream> #include<cstdio> #include<cstring> #include<vector> #include<algorithm> #include<cm…

最短路问题此类问题类型不多,变形较少 POJ 2449 Remmarguts' Date(中等)http://acm.pku.edu.cn/JudgeOnline/problem?id=2449题意:经典问题:K短路解法:dijkstra+A*(rec),方法很多相关:http://acm.pku.edu.cn/JudgeOnline/showcontest?contest_id=1144该题亦放在搜索推荐题中 POJ 3013 - Big Christmas Tree(基础)http://ac…

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…

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…