在一般的数据结构的书中，树的那章后面，著者一般都会介绍一下哈夫曼(HUFFMAN)树和哈夫曼编码。哈夫曼编码是哈夫曼树的一个应用。哈夫曼编码应用广泛，如JPEG中就应用了哈夫曼编码。

　　首先介绍什么是哈夫曼树。哈夫曼树又称最优二叉树，是一种带权路径长度最短的二叉树。所谓树的带权路径长度，就是树中所有的叶结点的权值乘上其到根结点的路径长度（若根结点为0层，叶结点到根结点的路径长度为叶结点的层数）。树的带权路径长度记为WPL=(W1*L1+W2*L2+W3*L3+...+Wn*Ln)，N个权值Wi(i=1,2,...n)构成一棵有N个叶结点的二叉树，相应的叶结点的路径长度为Li(i=1,2,...n)。可以证明哈夫曼树的WPL是最小的。-In the general data structure of the book, chapter and that the tree behind, the author will introduce the general Huffman (HUFFMAN) and Huffman coding tree. Huffman coding is an application of the Huffman tree. Huffman encoding applications, such as JPEG on the use of Huffman coding.

What is first introduced Huffman tree. Huffman tree is also called the optimal binary tree is a weighted length of the shortest path tree. The right tree with the so-called path length, is the tree of all the leaf nodes of the right value multiplied by its path length of the root node (root node is 0 if the layer of leaf nodes to root node of the path length for the leaf node layers). Tree path length with the right mind for the WPL = (W1* L1+ W2* L2+ W3* L3+...+ Wn* Ln), N a weight Wi (i = 1,2, ... n) constitute a trees have a N-leaf nodes of the tree, the corresponding leaf nodes of the path length for the Li (i = 1,2, ... n). Huffman tree can prove that the smallest of the WPL.