摘要：
题目链接： https://vjudge.net/problem/ZOJ-1456 These are N cities in Spring country. Between each pair of cities there may be one transportation track or n 阅读全文
摘要：
题目链接： https://vjudge.net/problem/POJ-3268 One cow from each of N farms (1 ≤ N ≤ 1000) conveniently numbered 1..N is going to attend the big cow party 阅读全文