UVALive - 4618 Wormholes(负环)】的更多相关文章

题目大意:给出出发点和终点和m个虫洞(虫洞的出发点.终点,生成时间和花费时间).问从起点到终点花费的最小时间 解题思路:关键是有负环,所以直接跑最短路算法的话会TLE.所以负环要处理一下 可是这个负环又不是负环.由于负环到一定程度的话.就会消失. 比方.到达时间小于虫洞的生成时间,那么负环就消失了.也就是说,负环内的点满足的最优情况就是到达时间刚好等于生成时间 所以,先找出负环,接着推断一下这个负环内的能节省的最多时间.然后将全部点都减去那个时间,那么负环就消失了 详细看代码 #include…
Wormholes Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 46123 Accepted: 17033 Description While exploring his many farms, Farmer John has discovered a number of amazing wormholes. A wormhole is very peculiar because it is a one-way path…
 POJ 3259 Wormholes Time Limit:2000MS     Memory Limit:65536KB     64bit IO Format:%lld & %llu   Description While exploring his many farms, Farmer John has discovered a number of amazing wormholes. A wormhole is very peculiar because it is a one-way…
题目链接:558 - Wormholes 题目大意:给出n和m,表示有n个点,然后给出m条边,然后判断给出的有向图中是否存在负环. 解题思路:利用Bellman Ford算法,若进行第n次松弛时,还能更新点的权值,则说明有负环的存在. #include <stdio.h> #include <string.h> #define min(a,b) (a)<(b)?(a):(b) const int N = 10005; const int INF = 0x3f3f3f3f; i…
Wormholes Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 24249   Accepted: 8652 Description While exploring his many farms, Farmer John has discovered a number of amazing wormholes. A wormhole is very peculiar because it is a one-way pa…
Wormholes Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 42366 Accepted: 15560 传送门 Description While exploring his many farms, Farmer John has discovered a number of amazing wormholes. A wormhole is very peculiar because it is a one-way p…
Wormholes Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 36729   Accepted: 13444 Description While exploring his many farms, Farmer John has discovered a number of amazing wormholes. A wormhole is very peculiar because it is a one-way p…
Wormholes Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 36425   Accepted: 13320 Description While exploring his many farms, Farmer John has discovered a number of amazing wormholes. A wormhole is very peculiar because it is a one-way p…
Description While exploring his many farms, Farmer John has discovered a number of amazing wormholes. A wormhole is very peculiar because it is a one-way path that delivers you to its destination at a time that is BEFORE you entered the wormhole! Eac…
Wormholes Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 49962   Accepted: 18421 Description While exploring his many farms, Farmer John has discovered a number of amazing wormholes. A wormhole is very peculiar because it is a one-way p…