数据结构--赫夫曼树及其应用
------ 赫夫曼树和赫夫曼编码的存储表示------
[cpp]
typedef struct {
unsigned int weight;
unsigned int parent,lchild,rchild;
}HTNode,*HuffmanTree;
typedef char ** HuffmanCode;
void HuffmanCoding(HuffmanTree& HT,HuffmanCode & HC,int *w,int n) {
if (n < 1) return;\
int m = 2* n + 1;
HT = (HuffmanTree) malloc (m+1)* sizeof(HTNode); //0 号单元未用
for ( HuffmanTree p = HT; i=1; i<=n; ++i; ++p; ++w)
*p = {*w,0,0,0,0};
for(; i<=m; ++i; ++p)
*p = {0,0,0,0};
for(i = n+1; i<=m; i++) { //建立HuffmanTree
Select(HT,i-1,s1,s2);
HT[s1].parent = i;
HT[s2].parent = i;
HT[i].lchild = s1;
HT[i].rchild = s2;
HT[i].weight = HT[s1].weight + HT[s2].weight;
}
HC = (HuffmanCode)malloc((n+1)* sizeof(char*));
cd = (char*) malloc(n* sizeof(char));
cd [n-1] = "\0";
for ( i=1; i<=n; i++) {
int start = n-1;
for ( c=i, f = HT[i].parent; f!=0; c=f; f = HT[f].parent )
if( HT[f].lchild == c ) cd [--start] = "0";
else cd [--start] = "1";
HC[i] = (char*) malloc ( (n-start)* sizeof(char));
strcyp(HC[i],&cd[start]);
}
free(cd);
}
------ 无栈非递归遍历赫夫曼树,求赫夫曼编码------
[cpp]
HC = (HuffmanCode) malloc ( (n+1) * sizeof(char*));
int p = m, cdlen = 0;
for ( int i=1; i<=m; ++i) HT[i].weight = 0;
while(p) {
if ( HT[p].weight == 0 ) {
HT[p].weight = 1;
if ( HT[p].lchild != 0) {
p = HT[p].lchild;
cd[cdlen++] = "0";
}else if ( HT[p].lchild == 0) {
HC[p] = (char*) malloc ((cdlen+1) * sizeof(char));
cd[cdlen] = "\0"; www.zzzyk.com
strcpy(HC[p],cd);
}
}else if ( HP[p].weight == 1) {
HT[p].weight = 2;
if ( HT[p].rchild != 0) {
p = HT[p].rchild;
cd [cdlen++] = "1";
}else {
HT[p].weight = 0; p = HT[p].parent; --cdlen;
}
}
}
补充:软件开发 , C++ ,