POJ 1161

第一道并查集，47ms ，还是很慢啊，不过是绞尽脑汁，调试了n次，做出来的，思路还是挺清晰地

 

#include <iostream>using namespace std;const int maxn=30010;int parent[maxn];int amount[maxn];int rank[maxn];int n,m;void init(){for(int i=0;i<n;i++){parent[i]=i;amount[i]=1;rank[i]=0;}}int find(int t){if(parent[t]!=t)return(find(parent[t]));return t;}void Union(int r1,int r2){if(rank[r1]>rank[r2]){parent[r2]=r1;amount[r1]+=amount[r2];}else{parent[r1]=r2;amount[r2]+=amount[r1];if(rank[r1]==rank[r2])rank[r2]++;}}int main(){while(scanf("%d%d",&n,&m)&&!(n==0&&m==0)){init();int i,j=0,g,f,r1,r2,t;for(i=0;i<m;i++){cin>>g;if(g){cin>>f;for(j=1;j<g;j++){cin>>t;r1=find(f);r2=find(t);if(r1!=r2){Union(r1,r2);}}}}int outcome=find(0);cout<<amount[outcome]<<endl;}return 0;}