Huffman编码

typedef struct {int weight;//结点的权值char bit[MAXBIT];//存放编码序号的数组int start;//编码的起始下标}HTCode,*HuffmanCode;//动态分配数组存储Huffman编码void HuffmanCoding( HuffmanTree &HT, HuffmanCode &HC, int n ){//求n个字符（叶子结点）的Huffman编码HCint i,j;int child,parent;HTCode cd;//临时存放编码HC = (HuffmanCode)malloc(n*sizeof(HTCode));//分配保存n个字符的编码空间for( i=0; i<n; i++ )//求n个叶子的Huffman编码{cd.start = MAXBIT - 1;//不等长编码的最后一位为MAXBIT-1cd.weight = HT[i].weight;//取得编码对应的权值child = i;//从第i个叶子结点开始parent = HT[child].parent;//parent指向child的双亲结点while( parent != -1 ){if( HT[parent].lchild == child )//child是其双亲的左孩子cd.bit[cd.start] = '0';//其分支赋值为'0'else//child是其双亲的右孩子cd.bit[cs.start] = '1';//其分支赋值为'1'cd.start--;//起始位置向前进一位child = parent;//child指向其双亲parent = HT[child].parent;//parent指向child的双亲结点}for( j=cd.start+1; j<MAXBIT; j++ )HC[i].bit[j] = cd.bit[j];//保存每个叶子的编码HC[i].start = cd.start + 1;//保存叶子结点编码的起始位HC[i].weight = cd.weight;//保存编码对应的权值}}

 

可用下面的程序测试构造HuffmanTree和HuffmanCode的相关操作。

void main(){int i,j,*w,n;HuffmanTree HT;HuffmanCode HC;cout<<"请输入权值的个数：";cin>>n;w = (int *)malloc(n*sizeof(int));//动态生成存放n个权值的空间cout<<"请依次输入"<<n<<"个权值（整型）";//依次输入权值for( i=0; i<n; i++ )cin>>w[i];HuffmanTreeing( HT, w, n );//根据w所存的n个权值构造HuffmanTreeHTHuffmanCoding( HT, HC, MAXBIT);//n个Huffman编码存于HCfor( i=0; i<n; i++ )//依次输入Huffman编码{cout<< "Weight = " << HT[i].weight << " Code = ";for( j=HC[i].start; j<MAXBIT; j++ )cout << HC[i].bit[j];cout << endl;}}