Huffman Coding Algorithm __ algorithm

Huffman.h
#ifndef __huffman_h_fe
#define __huffman_h_fe

The node structure of Huffman tree
typedef struct _HUFF_NODE ... {
float weight; Node weights
int lchild; node of the left child
int rchild; node of the right child
int parent; Node's parent node
} huff_node, * phuff_node;

Huffman Tree
typedef struct _HUFF_TREE ... {
int leaf_num; The Tree middle node is the number of nodes that need to be encoded
int node_num; Corresponding to the number of leaf nodes, Huffman tree in total need to 2*leaf_num-1 nodes
Phuff_node nodes; All nodes in the tree, with an array to store these nodes
char** Huff_code; Huffman coding for leaf nodes
} Huff_tree;

Initialize a Huffman tree, including the initialization of allocating space and weights for this tree.
void Init_huff_tree (FLOAT * weights, int leaf_num, Huff_tree & Tree);

Create a Huffman tree, if it must have been initialized
void Create_huff_tree (Huff_tree & Tree);

Print a tree has been created a good Huffman tree of the corresponding Huffman code
void Print_huff_code (Huff_tree & Tree);

Destroy a Huffman tree, release the initialization of the requested node and coding space
void Destroy_huff_tree (Huff_tree & Tree);

#endif

Huffman.cpp
#include < stdio.h >
#include < stdlib.h >
#include < float. h >
#include < Memory.h >
#include "Huffman.h"

void Huff_encode (Huff_tree & Tree);

Initialize a tree Huffman tree
void Init_huff_tree (FLOAT * weights, int leaf_num, Huff_tree & Tree)
... {
Save the number of leaf nodes
Tree.leaf_num = Leaf_num;

Calculate the number of nodes required by the whole Huffman tree according to the leaf node points
In a binary tree, the nodes with degrees 0, 1 and 2 have the following relationships:
n = n0 + n1 + n2 and n = n1 + 2*n2 + 1
Therefore, there are n2 = N0-1
In the Huffman tree, only the degree of 0 and 2 nodes
Therefore, n = n0 + N2 = 2*n0-1
Tree.node_num = 2 * leaf_num-1;

Allocate space for a node
Tree.nodes = new Huff_node[tree.node_num];
if (tree.nodes = NULL) ... {
printf ("Memry out.");
Exit (1);
}

Allocate stored Huffman-encoded character arrays for each leaf node
Tree.huff_code = new Char*[leaf_num];
if (Tree.huff_code = NULL) ... {
printf ("Memory out.");
Exit (1);
}