Huffman编码

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
//#pragma warning(disable:4996)

using namespace std;

typedef char **HuffmanCode;

typedef struct{
    int weight;
    int parent, lchild, rchild;
}HTNode, *HuffmanTree;


void Select(HuffmanTree HT, int n, int &s1, int &s2)
{
    int min1 = 100000, min2 = min1;
    for (int i = 1; i <= n; i++)
    {
        if (HT[i].weight <= min1 && HT[i].parent == 0)
        {
            min1 = HT[i].weight;
            s1 = i;
        }
    }
    HT[s1].parent = -1;
    for (int i = 1; i <= n; i++)
    {
        if (HT[i].weight <= min2 && HT[i].parent == 0)
        {
            min2 = HT[i].weight;
            s2 = i;
        }
    }
}

void CreatHuffmanTree(HuffmanTree &HT, int n)
{
    if (n <= 1) return;
    int m = 2 * n - 1, s1, s2;
    HT = new HTNode[m + 1];
    for (int i = 1; i <= m; ++i)
    {
        HT[i].lchild = 0;
        HT[i].rchild = 0;
        HT[i].parent = 0;
    }
    for (int i = 1; i <= n; ++i)
        cin >> HT[i].weight;
    for (int i = n + 1; i <= m; ++i)
    {
        Select(HT, i - 1, s1, s2);
        HT[s1].parent = HT[s2].parent = i;
        HT[i].lchild = s1;
        HT[i].rchild = s2;
        HT[i].weight = HT[s1].weight + HT[s2].weight;
    }
}

void CreatHuffmanCode(HuffmanTree HT, HuffmanCode &HC, int n)
{
    HC = new char*[n + 1];
    char *cd= new char[n];
    cd[n - 1] = '\0';
    for (int i = 1; i <= n; ++i)
    {
        int start = n - 1, c = i, f = HT[i].parent;
        while (f != 0)
        {
            --start;
            if (HT[f].lchild == c)
                cd[start] = '0';
            else
                cd[start] = '1';
            c = f;
            f = HT[f].parent;
        }
        HC[i] = new char[n - start];
        strcpy(HC[i], &cd[start]);
    }
    delete[] cd;
}

int main()
{
    int n;
    HuffmanTree HT;
    HuffmanCode HC;
    cout << "根据n个权值{ W1,W2....Wn }构造哈夫曼树.\n";
    cout << "输入权值个数n: ";
    cin >> n;
    cout << "输入n个权值：";
    CreatHuffmanTree(HT, n);
    CreatHuffmanCode(HT, HC, n);
    cout << "这n个权值的哈夫曼编码为:\n";
    for (int i = 1; i <= n; i++)
        cout << HC[i] << endl;
    return 0;
}

运行结果：