Huffman树

• 问题背景

• 策略
  • 每次合并重量最小的两堆，用堆来维护

练习

01 合并果子

• 题目

• 题解

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

public class huffmantree1 {
    public static int n;
    public static PriorityQueue<Integer> heap = new PriorityQueue<>();

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));
        n = Integer.parseInt(br.readLine());
        String[] str1 = br.readLine().split(" ");
        for (int i = 0; i < n; i++) {
            heap.offer(Integer.parseInt(str1[i]));
        }
        int res = 0;
        while (heap.size() != 1) {
            int a = heap.poll();
            int b = heap.poll();
            heap.offer(a + b);
            res += a + b;
        }
        pw.println(res);
        pw.close();
        br.close();
    }
}