Codeforces 209C. Trails and Glades(欧拉回路+并查集)

最新推荐文章于 2019-07-11 00:18:50 发布

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最新推荐文章于 2019-07-11 00:18:50 发布 · 344 阅读

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该博客讨论了Codeforces的一道题目209C——Trails and Glades，涉及欧拉回路和并查集的概念。问题要求确定是否有可能从第1个草地出发，走遍所有路径恰好一次并回到起点，若不行则需添加最少数量的路径。解题思路包括确保每个节点的度数为偶数，处理奇数度节点和连通分量的连接，以及独立点的特殊情况。代码实现中存在较多细节需要注意。

C. Trails and Glades

time limit per test

4 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

Vasya went for a walk in the park. The park has n glades, numbered from 1 to n. There are m trails between the glades. The trails are numbered from 1 to m, where the i-th trail connects glades xi and yi. The numbers of the connected glades may be the same (xi = yi), which means that a trail connects a glade to itself. Also, two glades may have several non-intersecting trails between them.

Vasya is on glade 1, he wants to walk on all trails of the park exactly once, so that he can eventually return to glade 1. Unfortunately, Vasya does not know whether this walk is possible or not. Help Vasya, determine whether the walk is possible or not. If such walk is imposs