Ice_cream's world I
Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 1830 Accepted Submission(s): 1060
Problem Description
ice_cream's world is a rich country, it has many fertile lands. Today, the queen of ice_cream wants award land to diligent ACMers. So there are some watchtowers are set up, and wall between watchtowers be build, in order to partition the ice_cream’s world. But how many ACMers at most can be awarded by the queen is a big problem. One wall-surrounded land must be given to only one ACMer and no walls are crossed, if you can help the queen solve this problem, you will be get a land.
Input
In the case, first two integers N, M (N<=1000, M<=10000) is represent the number of watchtower and the number of wall. The watchtower numbered from 0 to N-1. Next following M lines, every line contain two integers A, B mean between A and B has a wall(A and B are distinct). Terminate by end of file.
Output
Output the maximum number of ACMers who will be awarded.
One answer one line.
Sample Input
8 10 0 1 1 2 1 3 2 4 3 4 0 5 5 6 6 7 3 6 4 7
Sample Output
3
题目大意:富裕的ice_cream女王 要给ACMers分地,女王的土地中有很多瞭望塔,女王命令下人在瞭望塔 与瞭望塔之间建立笔直的围墙,被围墙圈起来的土地可以用来奖励ACMers,但是女王不知道最多能奖励多少ACMers,请你来帮忙。
这个题目是使用并查集来做的。关于并查集,我推荐两篇比较好的相关博文:
不知道为何我使用的java挂了,而使用C++的时候,同样的方法就AC了
下面给出代码: