随笔分类 -  图论

摘要：/*POJ 1860有多种汇币，汇币之间可以交换，这需要手续费，当你用100A币交换B币时，A到B的汇率是29.75，手续费是0.39，那么你可以得到(100 - 0.39) * 29.75 = 2963.3975 B币。问s币的金额经过交换最终得到的s币金额数能否增加货币的交换是可以重复多次的，所以我们需要找出是否存在正权回路，且最后得到的s金额是增加的怎么找正权回路呢？（正权回路：在这一回路上，顶点的权值能不断增加即能一直进行松弛）关键在于反向利用Bellman-Ford算法单源最短路径算法，因为题目可能存在负边，所以用Bellman Ford算法，原始Bellman Ford可以用来求负 阅读全文

摘要：CandiesTime Limit: 1500MSMemory Limit: 131072KTotal Submissions: 18737Accepted: 4930DescriptionDuring the kindergarten days, flymouse was the monitor of his class. Occasionally the head-teacher brought the kids of flymouse’s class a large bag of candies and had flymouse distribute them. All the kids 阅读全文

摘要：0 or 1Time Limit: 4000/2000 MS (Java/Others)Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 692Accepted Submission(s): 185Problem DescriptionGiven a n*n matrix Cij (1<=i,j<=n),We want to find a n*n matrix Xij (1<=i,j<=n),which is 0 or 1.Besides,Xij meets the following condi 阅读全文

摘要：Colored SticksTime Limit: 5000MSMemory Limit: 128000KTotal Submissions: 24748Accepted: 6519DescriptionYou are given a bunch of wooden sticks. Each endpoint of each stick is colored with some color. Is it possible to align the sticks in a straight line such that the colors of the endpoints that touch 阅读全文