uva 1160 - X-Plosives（并查集）

简单的并查集。

#include<cstdio>#define mx 100010int fa[mx];int find(int x){while(fa[x]!=x) x=fa[x];return x;}int main(){int i,x,y,cnt;while(scanf("%d",&x)!=EOF){for(i=0;i<mx;i++) fa[i]=i;cnt=0;while(x!=-1){scanf("%d",&y);x=find(x);y=find(y);if(x==y) cnt++;else fa[x]=y;scanf("%d",&x);}printf("%d\n",cnt);}return 0;}