HDU-1213 并查集裸题

#include #include #include #include #include #include #include #include #include #include using namespace std; typedef long long ll; #define DEBUG const int maxn=110000+5,maxv=26,INF=0x3f3f3f3f,mod=100000000; int n,m,p[maxn]; int find(int a){ return p[a]==a?a:find(p[a]); } int main(){ #ifdef DEBUG freopen("in.txt", "r", stdin); freopen("out.txt", "w", stdout); #endif int t; cin>>t; while(t--){ memset(p,0,sizeof(p)); cin>>n>>m; int a,b; for(int i=1; i<=n; i++) p[i]=i; while(m--){ cin>>a>>b; int pb=find(b),pa=find(a); if(pa!=pb) p[pa]=pb; } int ans=0; for(int i=1; i<=n; i++){ if(p[i]==i)ans++; } printf("%d\n",ans); } #ifdef DEBUG fclose(stdin); fclose(stdout); #endif return 0; }

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