记住几个最重要的公式: xANDy=0<=>(x=>y′)AND(y=>x′) xANDy=1<=>(x′=>x)AND(y′=>y) xORy=0<=>(x=>x′)AND(y=>y′) xORy=1<=>(x′=>y)AND(y′=>x) xXORy=0<=>(x′=>y′)AND(x=>y)AND(y=>x)AND(y′=>x′) xXORy=1<=>(x=…

POJ 3683 Priest John's Busiest Day / OpenJ_Bailian 3788 Priest John's Busiest Day(2-sat问题) Description John is the only priest in his town. September 1st is the John's busiest day in a year because there is an old legend in the town that the couple w…

Priest John's Busiest Day Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 10010   Accepted: 3425   Special Judge Description John is the only priest in his town. September 1st is the John's busiest day in a year because there is an old l…

题目地址:POJ 3683 第一次做须要输出可行解的题目. . .大体思路是先用强连通来推断是否有可行解,然后用逆序建图.用拓扑排序来进行染色.然后输出可行解. 详细思路见传送门 由于推断的时候少写了一个等号..检查了好长时间..sad... 代码例如以下: #include <iostream> #include <cstdio> #include <string> #include <cstring> #include <stdlib.h>…

Code Time Limit: 1000MS Memory Limit: 30000K Total Submissions: 8256 Accepted: 3906 Description Transmitting and memorizing information is a task that requires different coding systems for the best use of the available space. A well known system is t…

题意:有N场婚礼,每场婚礼的开始时间为Si,结束时间为Ti,每场婚礼有个仪式,历时Di,这个仪式要么在Si时刻开始,要么在Ti-Di时刻开始,问能否安排每场婚礼举行仪式的时间,使主持人John能参加所有的这些仪式的全过程. 题目链接:http://poj.org/problem?id=3683 ——>>每场婚礼的仪式,要么在开始段举行,要么在结束段举行,且一定要举行,要求各场婚礼仪式没冲突——>>2-SAT... 2-SAT挺神,针对此类问题,可谓手到擒来... LJ<训练指…

题目链接:http://poj.org/problem?id=3683 思路:对于每个结婚仪式,只有在开始或结束时进行这两种选择,我们可以定义xi为真当且仅当在开始时进行.于是我们可以通过时间先后确定矛盾关系,然后通过矛盾关系建图.至于输出一组可行解,就可以2次dfs(一次沿正向边,一次沿反向边)求出拓扑序,然后根据拓扑序输出可行解. http://paste.ubuntu.com/5983686/…

传送门:Problem 3683 https://www.cnblogs.com/violet-acmer/p/9769406.html 参考资料: [1]:挑战程序设计竞赛 题意: 有n场婚礼,每场婚礼有起始时间si,结束时间ti,还有一个主持仪式需要花费ti时间,ti必须安排在婚礼的开始或者结束. 主持由神父来做,但是只有一个神父,所以各个婚礼的主持时间不能重复,不过神父可以在出席完一个主持仪式后,立刻出席另一个开始时间与其结束时间相等的主持仪式,问你有没有可能正常的安排主持时间,不能输出n…

Priest John's Busiest Day Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 6900   Accepted: 2363   Special Judge Description John is the only priest in his town. September 1st is the John's busiest day in a year because there is an old le…

Priest John's Busiest Day Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 11127   Accepted: 3785   Special Judge Description John is the only priest in his town. September 1st is the John's busiest day in a year because there is an old l…