Ice_cream‘s world I
Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 603 Accepted Submission(s): 347
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
Author
Wiskey
Source
HDU 2007-10 Programming Contest_WarmUp
题意:
找到围成的环的个数。
代码如下:
#include<stdio.h> int father[10010]; int find(int r) { if(r!=father[r]) return find(father[r]); else return father[r]; } int main() { int n,m; while(~scanf("%d%d",&n,&m)) { int a,b,count=0; while(m--) { scanf("%d%d",&a,&b); int fa=find(a); int fb=find(b); if(fa==fb) count++;//判断是否有环,有的话,两者的父节点应该相等 else father[fa]=fb; } printf("%d\n",count); } return 0; }
hdu 2120 Ice_cream's world I(判断是否有环,简单的并查集)