POJ1988带权并查集

M u v 将u所在的堆移动到v所在的堆的上面

C u 求u的下面有多少块

带权并查集

import java.io.BufferedReader;import java.io.InputStream;import java.io.InputStreamReader;import java.io.PrintWriter;import java.math.BigInteger;import java.util.StringTokenizer;public class Main {public static void main(String[] args){           new Task().solve() ;}}class Task{final int N = 30000 ;int[] size = new int[N+8] ;int[] high = new int[N+8] ;int[] father = new int[N+8] ;void init(){for(int i = 1 ; i <= N ; i++){father[i] = i ;size[i] = 1 ;high[i] = 0 ;}}int getFather(int u){if(father[u] == u) return u ;int fu = father[u] ;int root = getFather(fu) ;high[u] += high[fu] ;return father[u] = root ;}void merge(int from , int to){int rootFrom = getFather(from) ;int rootTo = getFather(to) ;    high[rootTo] = size[rootFrom] ;    size[rootFrom] += size[rootTo] ;    father[rootTo] = father[rootFrom] ;}   void solve(){init() ;int p = in.nextInt() ;while(p-- > 0){if("M".equals(in.next())){int from = in.nextInt() ;int to = in.nextInt() ;     merge(from, to) ;}else{int u = in.nextInt() ;int root = getFather(u) ;out.println(size[root] - high[u] - 1) ;} }out.flush() ;}InputReader in = new InputReader(System.in) ;PrintWriter out = new PrintWriter(System.out) ;}class InputReader {      public BufferedReader reader;      public StringTokenizer tokenizer;        public InputReader(InputStream stream) {          reader = new BufferedReader(new InputStreamReader(stream), 32768);          tokenizer = new StringTokenizer("");      }        private void eat(String s) {          tokenizer = new StringTokenizer(s);      }        public String nextLine() {          try {              return reader.readLine();          } catch (Exception e) {              return null;          }      }        public boolean hasNext() {          while (!tokenizer.hasMoreTokens()) {              String s = nextLine();              if (s == null)                  return false;              eat(s);          }          return true;      }        public String next() {          hasNext();          return tokenizer.nextToken();      }        public int nextInt() {          return Integer.parseInt(next());      }        public long nextLong() {          return Long.parseLong(next());      }        public double nextDouble() {          return Double.parseDouble(next());      }        public BigInteger nextBigInteger() {          return new BigInteger(next());      }    }