C++實現哈夫曼樹編碼解碼

阿新 • • 發佈：2020-04-28

本文例項為大家分享了C++實現哈夫曼樹的編碼解碼，供大家參考，具體內容如下

程式碼：

#pragma once
#include<iostream>
#include<stack>
using namespace std;
#define m 20
stack<int> s;
/*哈夫曼樹結點類HuffmanNode宣告*/
template<class T>
class HuffmanNode {
private:
 HuffmanNode<T> * left;
 HuffmanNode<T> * right;
 T data;
 int weight;
public:
 HuffmanNode(){}
 HuffmanNode(const T& item,HuffmanNode<T> * l,HuffmanNode<T> * r):data(item),left(l),right(r){}
 HuffmanNode<T> * getLeft() { return left; }
 void setLeft(HuffmanNode<T> * left) { this->left = left; }
 HuffmanNode<T> * getRight() { return right; }
 void setRight(HuffmanNode<T> * right) { this->right=right; }
 T& getData() { return data; }
 void setData(const T& item) { data = item; }
 int getWeight() { return weight; }
 void setWeight(int weight) { this->weight = weight; }
};

/*哈夫曼樹類HuffmanTree宣告*/
template<class T>
class HuffmanTree {
private:
 HuffmanNode<T> * root;
 T data[m];
 int weight[m];
 int count;
public:
 HuffmanTree(HuffmanNode<T> * t=NULL):root(t){}
 void CreateHuffmanTree();//建立哈夫曼樹
 HuffmanNode<T> * getRoot() { return root; }
 void setRoot(HuffmanNode<T> * t) { root = t; }
 void inputNodes();//輸入各個結點的data和weight值
 HuffmanNode<T> * deCode(HuffmanNode<T>*t,T item);
 void showCode();
};

template<class T>
inline void HuffmanTree<T>::CreateHuffmanTree()
{
 inputNodes();
 HuffmanNode<T> ** H = new HuffmanNode<T>*[count];
 HuffmanNode<T> * p1 = NULL,*p2 = NULL,* p,* t;
 for (int i = 0; i < count; i++) {
 H[i] = new HuffmanNode<T>();
 H[i]->setData(data[i]);
 H[i]->setWeight(weight[i]);
 H[i]->setLeft(NULL);
 H[i]->setRight(NULL);
 }

 for (int i = 0; i < count - 1; i++) {
 p = new HuffmanNode<T>();
 p1 = H[i];
 p2 = H[i + 1];
 p->setLeft(p1);
 p->setRight(p2);
 p->setWeight(p1->getWeight() + p2->getWeight());
 //將新的結點插入結點陣列中的合適位置,並將被合併的兩個結點刪除
 t = p;
 int j = i + 2;
 while ( j < count &&H[j]->getWeight() < t->getWeight()) {
  H[j - 1] = H[j];
  j++;
 }
 H[j - 1] = t;
 }
 root = H[count - 1];
}

template<class T>
inline void HuffmanTree<T>::inputNodes()
{
 int i = 0;
 for (int j = 0; j < m; j++) {
 data[j] = NULL;
 weight[j] = 0;
 }
 while (cin >> data[i] >> weight[i]) {
 i++;
 }
 count = i;
}

template<class T>
inline HuffmanNode<T>* HuffmanTree<T>::deCode( HuffmanNode<T> * t,T item)
{
 HuffmanNode<T> * p,* q;
 if(t==NULL)
 return NULL;
 if (t->getData() == item)
 return t;
 if ((p = deCode(t->getLeft(),item))!=NULL) {
 s.push(0);
 return p;
 }
 else if((q = deCode(t->getRight(),item))!=NULL){
 s.push(1);
 return q ;
 }
}

template<class T>
inline void HuffmanTree<T>::showCode()
{
 cout << root->getWeight() << endl;
 cout << (root->getLeft())->getRight()->getData() << endl;
 for (int i = 0; i < count; i++) {
 cout << data[i] << "——";
 deCode(root,data[i]);
 while (!s.empty()) {
  cout << s.top();
  s.pop();
 }
 cout << endl;
 }
}

測試程式：

#include<iostream>
#include"HuffmanTree.h"
using namespace std;

int main() {
 HuffmanTree<char> * tree = new HuffmanTree<char>();
 tree->CreateHuffmanTree();
 tree->showCode();
 system("pause");
 return 0;
}

測試資料：

n 1
s 3
t 4
a 10
i 12
p 13
e 15
Ctrl+Z 回車結束輸入
輸入時權值由小到大排序…也可以在程式里加一個排序

結果：

C++實現哈夫曼樹編碼解碼