该思想借鉴于《2019版数据结构高分笔记(c语言版)》- 第7版

最近事多，有时间会把思路在这里阐述一下

代码思路如下/*

*

* add() 输入names[] weights[]

* sort()排序

* generateTree()生成树

* preOrder() 先序遍历生成节点编码code

* inOrder() 前序遍历输出编码

*

* root

* / \

* B tem

* / \

* D tem

* / \

* C tem

* / \

* A tem

* / \

* E F

* */代码如下package COURSE;

import java.util.LinkedList;

public class HuffmanTree {

private class Node {

E data;

double weight;

Node left, right;

String code = null;

// 叶子节点

public Node(E data, double weight) {

this.data = data;

this.weight = weight;

left = null;

right = null;

}

// 中间节点

public Node(Node left, Node right) {

this.data = null;

this.weight = left.weight + right.weight;

this.left = left;

this.right = right;

}

@Override

public String toString() {

StringBuilder res = new StringBuilder();

res.append("(data = ").append(data).append(", weight = ").append(weight).append("," + "code=").append(code).append(")");

return res.toString();

}

}

int size;

Node root;

LinkedList nodes = new LinkedList<>();

private String nodeCode = ""; // 左0 右1

public HuffmanTree() {

size = 0;

root = null;

}

// 添加： 批量添加

public void add(Character[] names, Double[] weights) {

for (int i = 0; i < names.length; i++) {

add((E) names[i], weights[i]);

}

}

private void add(E data, double weight) {

Node node = new Node(data, weight);

nodes.add(node);

size++;

}

// 排序

private void sort() {

LinkedList newNodes = new LinkedList<>();

while (!nodes.isEmpty()) {

int index = 0;

for (int i = 0; i < nodes.size(); i++) {

if (nodes.get(index).weight < nodes.get(i).weight) {

index = i;

}

}

newNodes.add(nodes.remove(index));

}

nodes = newNodes;

System.out.print("排序结果为");

System.out.println(nodes);

}

// 生成树

private void generateTree() {

Node min1 = nodes.removeLast();

Node min2 = nodes.removeLast();

Node temNode = new Node(min1, min2);

while (!nodes.isEmpty()) {

Node minNode = nodes.removeLast();

temNode = new Node(minNode, temNode);

}

this.root = temNode;

}

// 私有：前序遍历 + 编码

private void preOrder(Node node) {

Node cur = node;

if (cur.left != null) {

nodeCode = nodeCode + "0";

preOrder(cur.left);

}

if (cur.right != null) {

nodeCode = nodeCode + "1";

preOrder(cur.right);

}

if (cur.left == null && cur.right == null && cur.data != null) {

cur.code = nodeCode;

System.out.println("节点" + cur.data + "的编码为" + cur.code);

nodeCode = nodeCode.substring(0,nodeCode.length() -1);

return;

}

}

// 中序遍历

public void inOrder() {

sort(); // 排序

generateTree(); // 生成树

preOrder(root);// 编码

inOrder(root); // 遍历

}

// 私有 ： 中序遍历递归

private void inOrder(Node node) {

if (node == null) {

return;

}

inOrder(node.left);

if (node.data != null) {

System.out.println(node);

}

inOrder(node.right);

}

public static void main(String[] args) {

Character[] names = {'A', 'B', 'C', 'D', 'E', 'F'};

Double[] weights = {15.0, 30.0, 20.0, 25.0, 3.0, 7.0};

HuffmanTree huffmanTree = new HuffmanTree();

huffmanTree.add(names, weights);

huffmanTree.inOrder();

}

}