hdu 1232 并查集

水。。。。求集合个数-1就行= = #include<cstdio>#include<stdlib h="">#include<string h="">#include<string>#include<cmath>#include<cstring>#include#include<map>#include<set>#include<queue>#include<vector>using namespace std;int f[5005];int find(int x){ if(x==f[x]) return x; else return f[x]=find(f[x]);}bool same(int x,int y){ x=find(x); y=find(y); if(x==y) return true; else return false;}void unite(int x,int y){ x=find(x); y=find(y); f[x]=y;}int main(){ map<int int=""> x;// freopen("in.txt","r",stdin);// freopen("out.txt","w",stdout); int n,m,i,a,b; while(scanf("%d%d",&n,&m)!=EOF){ if(n==0) break; x.clear(); for(i=1;i<=n;i++) f[i]=i; for(i=0;i<m;i++){ scanf("%d%d",&a,&b); unite(a,b); } for(i=1;i<=n;i++) { int k=find(i); x[k]=1; } printf("%d\n",x.size()-1); } return 0;}</int></vector></queue></set></map></algorithm></cstring></cmath></string></string></stdlib></cstdio>