POJ 1988

【题目分析】
并查集。

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【代码】

#include <cstdio>#include <cmath>#include <cstring>#include <iostream>#include <algorithm>using namespace std;int f[50001],w[50001],s[50001];char ss[11];inline int gf(int k){    if (f[k]==k) return k;    int t=f[k];    f[k]=gf(f[k]);    w[k]+=w[t];    return f[k];}inline void un(int x,int y){    x=gf(x);y=gf(y);    f[x]=y;    w[x]+=s[y];    s[y]+=s[x];    s[x]=0;}int main(){    int n;    scanf("%d",&n);    for (int i=1;i<=30000;++i) f[i]=i,w[i]=0,s[i]=1;    while (scanf("%s",ss)!=EOF)    {//      printf("%s\n",s);        if (ss[0]=='M'){            int x,y;            scanf("%d%d",&x,&y);            un(x,y);        }        else{            int x;            scanf("%d",&x);            gf(x);            printf("%d\n",w[x]);        }    }}