CF938D Buy a Ticket

Musicians of a popular band "Flayer" have announced that they are going to "make their exit" with a world tour. Of course, they will visit Berland as well. There are $ n $ cities in Berland. People can travel between cities using two-directional train routes; there are exactly $ m $ routes, $ i $ -th route can be used to go from city $ v_{i} $ to city $ u_{i} $ (and from $ u_{i} $ to $ v_{i} $ ), and it costs $ w_{i} $ coins to use this route. Each city will be visited by "Flayer", and the cost of the concert ticket in $ i $ -th city is $ a_{i} $ coins. You have friends in every city of Berland, and they, knowing about your programming skills, asked you to calculate the minimum possible number of coins they have to pay to visit the concert. For every city $ i $ you have to compute the minimum number of coins a person from city $ i $ has to spend to travel to some city $ j $ (or possibly stay in city $ i $ ), attend a concert there, and return to city $ i $ (if $ j≠i $ ). Formally, for every  you have to calculate , where $ d(i,j) $ is the minimum number of coins you have to spend to travel from city $ i $ to city $ j $ . If there is no way to reach city $ j $ from city $ i $ , then we consider $ d(i,j) $ to be infinitely large.

N/A

N/A