Huffman树的编码译码

上个学期做的课程设计，关于Huffman树的编码译码。

要求：

输入Huffman树各个叶结点的字符和权值，建立Huffman树并执行编码操作

输入一行仅由01组成的电文字符串，根据建立的Huffman树进行译码操作，程序最后输出译码后的结果

Huffman.h定义了树的结点信息，各种操作。GCC编译通过。

#ifndef HUFFMAN_H_INCLUDED
#define HUFFMAN_H_INCLUDED
#include <iostream>
#include <stdlib.h>
#include <string>

#define leafNumber 20
#define totalNumber 39
#define maxValue 100
using namespace std;

//权值类型, 这里定义为int
typedef int WType;

//树的结点类型, 这里定义为char, 表示字符
typedef char TElemType;

//Huffman树结点信息定义
typedef struct HuffmanNode{
    TElemType data;
    WType weight;
    int left_child;
    int right_child;
    int parent;
    string code;    //每个结点的编码, 定义为 string 类
};

//Huffman树结构定义
typedef struct HuffmanTree{
    HuffmanNode elem[totalNumber];
    int currentNumber;
};

/*
*构建Huffman树
*/
void createHuffmanTree( HuffmanTree &HT, WType w[], int n ) {
    int i, j, p1, p2, min1, min2;
    for( i = 0; i < n; i++ ) HT.elem[i].weight = w[i];
    for( i = 0; i < 2 * n - 1; i++ )
        HT.elem[i].parent = HT.elem[i].left_child = HT.elem[i].right_child = -1;
    for( i = n; i < 2 * n - 1; i++ ) {
        min1 = min2 = maxValue;
        for( j = 0; j < i; j++ ) {
            if( HT.elem[j].parent == -1 )
                if( HT.elem[j].weight < min1 ) {
                    p2 = p1;
                    min2 = min1;
                    p1 = j;
                    min1 = HT.elem[j].weight;
                }
                else if( HT.elem[j].weight < min2 ) {
                    p2 = j;
                    min2 = HT.elem[j].weight;
                }
        }
        HT.elem[i].left_child = p1;
        HT.elem[i].right_child = p2;
        HT.elem[i].weight = HT.elem[p1].weight + HT.elem[p2].weight;
        HT.elem[p1].parent = HT.elem[p2].parent = i;
    }
    HT.currentNumber = 2 * n - 1;
}

/*
*对Huffman树每个结点进行编码
*/
void Coding( HuffmanTree &HT, int n ) {

    //当前节点下标
            int current = 0;
            //父节点下标
            int parent = 0;
    for( int i = 2 * n - 2 ; i >= 0; i-- ) {

        current = i;
        parent = HT.elem[current].parent;
        /*
        if( parent == -1 ) HT.elem[current].code[0] = '0';
        else {
            if( HT.elem[parent].left_child == current ) {
                strcat( HT.elem[current].code, HT.elem[parent].code );
                strcat( HT.elem[current].code, "0" );
            }
            if( HT.elem[parent].right_child == current ) {
                strcat( HT.elem[current].code, HT.elem[parent].code );
                strcat( HT.elem[current].code, "1" );
            }
        }
        */


        while (parent != -1)
                {
                    if (HT.elem[parent].left_child == current) HT.elem[i].code += "0";
                    else HT.elem[i].code += "1";

                    current = parent;
                    parent = HT.elem[current].parent;
                }

        //HT.elem[current].code += "0";
        reverse( HT.elem[i].code.begin(), HT.elem[i].code.end() );

    }

}

/*
*译码
*/
void decode( HuffmanTree &HT, int n ) {
    cout << "输入电文: ";
    char ch[100];
    gets( ch );

    int i = 0;
    int parent;
    int root = 2 * n - 2;
    int index = root;
    int count = 0;
    int len = strlen( ch );
    while( ch[i] != '#' ) {
        if( ch[i] == '0' ) {
            index = HT.elem[index].left_child;
            //cout << "经过0" << endl;
            //cout << index << endl;
            //count++;
        }
        else if( ch[i] == '1' ) {
            index = HT.elem[index].right_child;
            //cout << "经过1" << endl;
            //cout << index << endl;
            //count++;
        }
        if( HT.elem[index].left_child == -1 && HT.elem[index].right_child == -1 ) {
            cout << HT.elem[index].data;
            index = root;
            //i += count;
            //count = 0;
            //cout << index << endl;
        }
        i++;
    }
}
/*
*遍历
*/
void PreOrder( HuffmanTree &HT, int n ) {
    for( int i = 0; i < n; i++ ) {
        cout << "字符: " << HT.elem[i].data << ", " << "权值: " << HT.elem[i].weight << "  Huffman编码: " << HT.elem[i].code << endl;
    }
};


#endif // HUFFMAN_H_INCLUDED

#include "Huffman.h"
int main() {
    HuffmanTree HT;
    HT.elem[0].data = 'A';
    HT.elem[1].data = 'B';
    HT.elem[2].data = 'C';
    HT.elem[3].data = 'D';
    HT.elem[4].data = 'E';
    WType weight[] = { 7, 5, 2, 4, 6 };
    //WType weight[] = { 5,7,2,13 };
    createHuffmanTree( HT, weight, 5 );
    Coding( HT, 5 );
    PreOrder( HT, 5 );

    cout << endl << endl;
    for( int i = 0; i < 9; i++ )
        cout << "Node " << i << " Code: " << HT.elem[i].code << endl;

    cout << endl << endl;
    for( int i = 0; i < 9; i++ ) {
        cout << "Node " << i << ": " << "weight = " << HT.elem[i].weight << ", parent = " << HT.elem[i].parent << ", left_child = " << HT.elem[i].left_child
                << ", right_child = " << HT.elem[i].right_child << endl;
    }
    decode( HT, 5 );
    return 0;
}

运行截图：