Huffman树的创建

Huffman树，又称最优树，是一类带权路径长度最短的树。

在解决某些判定问题时，Huffman树可

#include <iostream>
#include <cstring>
using namespace std;
#define MAXBIT      20
#define MAXLEAF     30
#define MAXNODE    59

typedef struct
{
	int bit[MAXBIT];
	int start;
} HCodeType; 
typedef struct
{
	int weight;
	int parent;
	int lchild;
	int rchild;
} HNodeType;

void HuffmanTree(HNodeType HuffNode[MAXNODE], int n)
{
	/* i、j： 循环变量，m1、m2：构造哈夫曼树不同过程中两个最小权值结点的权值，
	x1、x2：构造哈夫曼树不同过程中两个最小权值结点在数组中的序号。*/
	int i, j, m1, m2, x1, x2;
	for (i = 0; i<2 * n - 1; i++)
	{
		HuffNode[i].weight = 0;
		HuffNode[i].parent = -1;
		HuffNode[i].lchild = -1;
		HuffNode[i].rchild = -1; 
	}
	cout << "依次输入叶子结点的权值："<<endl;
	for (i = 0; i<n; i++)
	{
		cin>>HuffNode[i].weight;
	}
	for (i = 0; i<n - 1; i++)
	{
		m1 = m2 = 32767; 
		x1 = x2 = 0;
		for (j = 0; j<n + i; j++)
		{
			if (HuffNode[j].weight < m1 && HuffNode[j].parent == -1)
			{
				m2 = m1;
				x2 = x1;
				m1 = HuffNode[j].weight;
				x1 = j;
			}
			else if (HuffNode[j].weight < m2 && HuffNode[j].parent == -1)
			{
				m2 = HuffNode[j].weight;
				x2 = j;
			}
		} 
		HuffNode[x1].parent = n + i;
		HuffNode[x2].parent = n + i;
		HuffNode[n + i].weight = HuffNode[x1].weight + HuffNode[x2].weight;
		HuffNode[n + i].lchild = x1;
		HuffNode[n + i].rchild = x2;
	} 
} 

void huffmancode(HCodeType HuffCode[MAXLEAF], HNodeType HuffNode[MAXNODE],int n)
{
	HCodeType cd;
	int i, j,c,p;
	for (i = 0; i < n; i++)
	{
		cd.start = n - 1;
		c = i;
		p = HuffNode[c].parent;
		while (p != -1) 
		{
			if (HuffNode[p].lchild == c)
				cd.bit[cd.start] = 0;
			else
				cd.bit[cd.start] = 1;
			cd.start--;  
			c = p;
			p = HuffNode[c].parent;   
		} 
		for (j = cd.start + 1; j<n; j++)
		{
			HuffCode[i].bit[j] = cd.bit[j];
		}
		HuffCode[i].start = cd.start;
	}
	cout << "各个结点的huffman编码依次是："<<endl;
	for (i = 0; i<n; i++)
	{
		for (j = HuffCode[i].start + 1; j < n; j++)
		{
			cout<<HuffCode[i].bit[j];
		}
		cout << endl;

	}

}

int main(void)
{
	HNodeType HuffNode[MAXNODE];   
	HCodeType HuffCode[MAXLEAF];  
	int  n;
	cout << "输入叶子结点的个数："<<endl;
	cin>>n;
	HuffmanTree(HuffNode, n);
	huffmancode(HuffCode,HuffNode,n);
	system("pause");
	return 0;
}

以得到最佳的判定算法。