1234: ZJTZYRC筛offer（并查集 ）

链接：http://xcacm.hfut.edu.cn/problem.php?id=1234

以后关于字符的输入都用cin吧，换成scanf居然wa了

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <map>
#include <string>
#include <set>
#define Max 10005
using namespace std;
int pre[Max],Rank[Max];
int sum;
void init()
{
    for(int i=0;i<Max;i++)
        pre[i]=i;
    return;
}
int find(int x)
{
    if(pre[x]==x)
        return x;
    return pre[x]=find(pre[x]);
}
int unite(int a,int b)
{
    int x=find(a);
    int y=find(b);
    if(Rank[x]==Rank[y])
        return 0;
    sum--;
    if(Rank[x]<Rank[y])
        pre[y]=x;
    else
        pre[x]=y;
    return 0;
}
int main()
{
    int n,m;
    char ch;
    string s,a,b;
    map<string,int> u;
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    while(scanf("%d",&n)!=EOF)
    {
        sum=n;
        u.clear();
        init();
        for(int i=0;i<n;i++)
        {
            cin>>s;
            u[s]=i+1;
            Rank[i+1]=i+1;
        }
        cin>>m;
        for(int i=0;i<m;i++)
        {
            cin>>ch;
            if(ch=='a')
            {
                cin>>a>>b;
                unite(u[a],u[b]);
            }
            else if (ch=='q')
            {
                cin>>a;
                int r=find(u[a]);
                printf("%d
",Rank[r]);
            }
            else if (ch=='t')
                printf("%d
",sum);
        }    
    }    
    return 0;
}