2017 "Wisdom Information Cup" Chinese undergraduate Program Design Competition National Invitational Contest (Hunan) and the nineth session of Xiangtan College Students Program Competition H.highway (diameter of the tree)

Highway
accepted:122		submit:393
Time limit:4000 MS		Memory limit:65536 KB

Highway In Icpccamp there were n towns conveniently numbered with 1,2,..., N connected with (n−1) roads. The I-th road connecting towns AI and bi has length ci. It is guaranteed the any two cities to the other using only roads. Bobo would like "build" (n−1) highways so and any two towns reach each using only highways. Building a highway between towns X and y costs himδ (x,y) Cents, whereδ (x,y) is the length of the shortest path between t owns X and y using roads. As Bobo is rich, he would the most expensive way to build the n−1. Input The input contains zero or more test cases and are terminated by End-of-file. For each test case: The contains an integer n. The i-th of the following (n−1) lines contains three integers AI