原题出处:HDOJ Problem Index by Type,http://acm.hdu.edu.cn/typeclass.php
杭电OJ分类题目(4)
HDU Graph Theory - Union-Find Sets
HDU Graph Theory - Match
HDU Graph Theory - Network Flow
HDU Graph Theory - Shortest Path
HDU Graph Theory - Assignment Problem
HDU Graph Theory - Minimum Spanning Tree
HDU Graph Theory - Others