题目链接 题意:平面上,一个圆,圆的边上按顺时针放着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,每个点最多只会连接的一条边.问能不能连接这m条边,使这些边都不相交. 分析:将每一条边缩成一个点,对于每条边要么在圆内要么在园外只有满足一种情况,将在圆内设为i,在圆外设为i',那么对于两条线(i, j)不能同时在圆内,那么也不能同时在圆外.则有四种情况 (i, j') (i', j) (j, i') (j', i)要建这四条边,然后就照着刘汝…

Ikki's Story IV - Panda's Trick Time Limit: 1000MS   Memory Limit: 131072KB   64bit IO Format: %I64d & %I64u Submit Status Description liympanda, one of Ikki's friend, likes playing games with Ikki. Today after minesweeping with Ikki and winning so m…

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…

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…

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…

题意: 平面上,一个圆,圆的边上按顺时针放着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,每个点最多只会连接的一条边.问能不能连接这m条边,使这些边都不相交. 解题报告: 题意可能刚开始不是很好理解,比如1 5连边,2,6连边,由于点是顺序排列的,一画图就可以发现,这两条边必须一个从圆外面连,一个从内部连,否则就会相交.如果再加入3 7这条边,那么就必须相交了. 这样,就可以转化成标准的2-sta问题: 1:每个边看成2个点:分别表示在内部…

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…

http://poj.org/problem?id=3207 题意:一个圆上顺时针依次排列着标号为1-n的点,这些点之间共有m条边相连,每两个点只能在圆内或者圆外连边.问是否存在这些边不相交的方案.(n<=1000, m<=500) #include <cstdio> #include <cstring> #include <algorithm> #include <cmath> #include <iostream> using n…