很巧妙的建边方式 题意:有n个区域,每个区域有一些人数si和食物bi,区域之间有m条定向路径,每条路径有人数通过上限ci.路径之间铺了电线,每当有人通过路径时有pi的概率会触碰到电线,但是第一个通过的人一定不会触碰到电线.求每个人都通过路径获取到食物后触碰到电线的最小概率. 解法:不碰到电线的概率比较好求,然后对于一条路线上的不碰到电线的概率是(1-p1)*(1-p2)...,最小费用流是没法跑乘法的,所以我们建边的费用变成log(1-p),那么乘法就变成了加法,然后要求最小值,由于log(1-…

Different Circle Permutation Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 208    Accepted Submission(s): 101 Problem Description You may not know this but it's a fact that Xinghai Square is…

Barricade Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 997    Accepted Submission(s): 306 Problem Description The empire is under attack again. The general of empire is planning to defend his…

2016 ACM/ICPC Asia Regional Qingdao Online(部分题解) 5878---I Count Two Three http://acm.hdu.edu.cn/showproblem.php?pid=5878 Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1287    Accepted Submissi…

I Count Two Three Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 782    Accepted Submission(s): 406 Problem Description I will show you the most popular board game in the Shanghai Ingress Resis…

Friends and Enemies Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 291    Accepted Submission(s): 160 Problem Description On an isolated island, lived some dwarves. A king (not a dwarf) ruled t…

Function Time Limit: 7000/3500 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 976    Accepted Submission(s): 375 Problem Description The shorter, the simpler. With this problem, you should be convinced of this tru…

Football Games Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 802    Accepted Submission(s): 309 Problem Description A mysterious country will hold a football world championships---Abnormal Cup…

Sparse Graph Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 689    Accepted Submission(s): 238 Problem Description In graph theory, the complement of a graph G is a graph H on the same vertic…

hannnnah_j’s Biological Test Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 802    Accepted Submission(s): 269 Problem Description hannnnah_j is a teacher in WL High school who teaches biolog…