CF1296F.Berland Beauty
普及/提高-
通过率:0%
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题目描述
There are n railway stations in Berland. They are connected to each other by n−1 railway sections. The railway network is connected, i.e. can be represented as an undirected tree.
You have a map of that network, so for each railway section you know which stations it connects.
Each of the n−1 sections has some integer value of the scenery beauty. However, these values are not marked on the map and you don't know them. All these values are from 1 to 106 inclusive.
You asked m passengers some questions: the j -th one told you three values:
- his departure station aj ;
- his arrival station bj ;
- minimum scenery beauty along the path from aj to bj (the train is moving along the shortest path from aj to bj ).
You are planning to update the map and set some value fi on each railway section — the scenery beauty. The passengers' answers should be consistent with these values.
Print any valid set of values f1,f2,…,fn−1 , which the passengers' answer is consistent with or report that it doesn't exist.
输入格式
The first line contains a single integer n ( 2≤n≤5000 ) — the number of railway stations in Berland.
The next n−1 lines contain descriptions of the railway sections: the i -th section description is two integers xi and yi ( 1≤xi,yi≤n,xi=yi ), where xi and yi are the indices of the stations which are connected by the i -th railway section. All the railway sections are bidirected. Each station can be reached from any other station by the railway.
The next line contains a single integer m ( 1≤m≤5000 ) — the number of passengers which were asked questions. Then m lines follow, the j -th line contains three integers aj , bj and gj ( 1≤aj,bj≤n ; aj=bj ; 1≤gj≤106 ) — the departure station, the arrival station and the minimum scenery beauty along his path.
输出格式
If there is no answer then print a single integer -1.
Otherwise, print n−1 integers f1,f2,…,fn−1 ( 1≤fi≤106 ), where fi is some valid scenery beauty along the i -th railway section.
If there are multiple answers, you can print any of them.
输入输出样例
输入#1
4 1 2 3 2 3 4 2 1 2 5 1 3 3
输出#1
5 3 5
输入#2
6 1 2 1 6 3 1 1 5 4 1 4 6 1 3 3 4 1 6 5 2 1 2 5
输出#2
5 3 1 2 1
输入#3
6 1 2 1 6 3 1 1 5 4 1 4 6 1 1 3 4 3 6 5 3 1 2 4
输出#3
-1