题意: 就是一个圈上有n个点,给出m对个点,这m对个点,每一对都有一条边,合理安排这些边在圈内或圈外,能否不相交 解析: 我手残 我手残 我手残 写一下情况 只能是一个在圈外 一个在圈内 即一个1一个0 #include <iostream> #include <cstdio> #include <sstream> #include <cstring> #include <map> #include <cctype> #include…

Code: #include<cstdio> #include<algorithm> #include<vector> using namespace std; const int maxn=3000; int c=0; int mark[maxn],S[maxn],from[maxn],to[maxn]; vector<int>G[maxn]; void add_edge(int x,int y){ x=(x*2)+1,y=(y*2)+1; G[x-1].…

Ikki's Story IV - Panda's Trick Time Limit: 1000MS   Memory Limit: 131072K Total Submissions: 7296   Accepted: 2705 Description liympanda, one of Ikki’s friend, likes playing games with Ikki. Today after minesweeping with Ikki and winning so many tim…

http://poj.org/problem?id=3207 Ikki's Story IV - Panda's Trick Time Limit: 1000MS   Memory Limit: 131072K Total Submissions: 7021   Accepted: 2604 Description liympanda, one of Ikki’s friend, likes playing games with Ikki. Today after minesweeping wi…

POJ 3207 Ikki's Story IV - Panda's Trick(2-sat问题) Description liympanda, one of Ikki's friend, likes playing games with Ikki. Today after minesweeping with Ikki and winning so many times, he is tired of such easy games and wants to play another game…

Ikki's Story IV - Panda's Trick Time Limit: 1000MS   Memory Limit: 131072K Total Submissions: 6691   Accepted: 2496 Description liympanda, one of Ikki’s friend, likes playing games with Ikki. Today after minesweeping with Ikki and winning so many tim…

POJ 3207 Ikki's Story IV - Panda's Trick liympanda, one of Ikki's friend, likes playing games with Ikki. Today after minesweeping with Ikki and winning so many times, he is tired of such easy games and wants to play another game with Ikki. liympanda…

题目链接:http://poj.org/problem?id=3207 题意:在一个圆圈上有n个点,现在用线把点两两连接起来,线只能在圈外或者圈内,现给出m个限制,第 i 个点和第 j 个点必须链接在一起,问是否存在可行解. 容易想到圈内和圈外分别表示2sat的两种状态,对每一个限制 i 和 j ,考虑所有其它横跨他们的限制,然后连边就可以了. //STATUS:C++_AC_47MS_6300KB #include <functional> #include <algorithm>…

poj3207:http://poj.org/problem?id=3207 题意::平面上有一个圆,圆的边上按顺时针放着0..n-1共n个点.现在要连m条边,比如a,b,那么a到b可以从圆的内部连接,也可以从圆的外部连接.给你的信息中,每个点最多只能连一条边.问是否可以连接这m条边,使这些边都不相交. 题解:第一道2-sat.看了别人的题解,才理解了这样的想法.对于一条边,要么在圆内要么在圆外.两条相交的边不能同时在园内或者同时在圆外,所以一条在园内,一条在圆外.这样就是2-sat问题了.这一…

题目传送门 题意:在一个圆上顺时针安放着n个点,给出m条线段连接端点,要求线段不相交,线段可以在圆内也可以在圆外,问是否可以. 思路:假设一条线段,放在圆外是A,放在园内是A',那么两条线段如果必须一个放圆内一个放圆外的条件就是 端点区间相交(严格相交),所以就建立了2-SAT模型,然后跑2-SAT的模板就可以了. //#include<bits/stdc++.h> #include<stdio.h> #include<iostream> #include<std…