POJ 2524 Ubiquitous Religions "and check set"

Problem-Solving Ideas: Enter the total number of N, and M group data, that is, and Hangzhou electric Smooth engineering, similar to the M group of data to do the merger, the last number of areas to find a total.

#include <stdio.h>int pre[50001];int find (int root) {if (Root!=pre[root]) Pre[root]=find (Pre[root]); return pre[ Root];} void Unionroot (int x,int y) {int root1,root2;root1=find (x); Root2=find (y); if (x!=y) {Pre[root1]=root2;}} int main () {int n;int i;int x,y;long int m;int tag=1;while (scanf ("%d%d", &n,&m)!=eof&& (n| | m) {int sum=0;for (i=0;i<n;i++) pre[i]=i;while (m--) {scanf ("%d%d", &x,&y); Unionroot (x, y);} for (i=0;i<n;i++) {if (Find (i) ==i) sum++;} printf ("Case%d:%d\n", tag,sum); tag++;}}

POJ 2524 Ubiquitous Religions "and check set"