题目描述

算法1

Java 代码

import java.io.*;
import java.util.*;

public class Main {

    static class UFind {
        int[] father; 
        int[] size;
        UFind(int n){
            father = new int[n+1];
            size = new int[n+1];
            for(int i = 1; i <= n; i++){
                father[i] = i;
                size[i] = 1;
            }
        }

        public int find(int x) { 
            if(father[x] != x){
                father[x] = find(father[x]);
            }
            return father[x];
        }

        public void union(int p, int q) { 
            int fp = find(p);
            int fq = find(q);
            if(fp != fq){
                father[fp] = fq;
                size[fq] += size[fp];
            }
        }
    }

    static BufferedReader read = new BufferedReader(new InputStreamReader(System.in));
    static BufferedWriter log  = new BufferedWriter(new OutputStreamWriter(System.out));
    public static void main(String[] args) throws Exception {
        String[] s = read.readLine().split(" ");
        int n = Integer.valueOf(s[0]);
        int m = Integer.valueOf(s[1]);
        UFind uf = new UFind(n);
        for(int i = 0; i < m; i++){
            s = read.readLine().split(" ");
            if("C".equals(s[0])){
                uf.union(Integer.valueOf(s[1]), Integer.valueOf(s[2]));
            }else if("Q1".equals(s[0])){
                int f1 = uf.find(Integer.valueOf(s[1]));
                int f2 = uf.find(Integer.valueOf(s[2]));
                String out = f1 == f2 ? "Yes" : "No";
                log.write(out + "\n");
            }else{
                int f = uf.find(Integer.valueOf(s[1]));
                log.write(uf.size[f] + "\n");
            }
        }
        log.flush();
    }
}