huffman树的建立

huffman树的建立

Huffman树：所有结点带权路径长度之和最小的树

将权重结点（left right设为null）输入堆的指针数组中，再排成最小堆，每次取出两个，建立新结点t，把两个最小结点挂在t上，再将t插入最小堆，每个结点合并一次，共需h->size次

typedef struct treenode {
    
    
	int weight;
	huffmantree left;
	huffmantree right;
}*huffmantree;

typedef struct hfnode {
    
    
	huffmantree *data;
	int size;
	int maxsize;
}*hfheap;

hfheap buildminheap(hfheap h);

huffmantree huffman(hfheap h) {
    
    
	int i;
	buildminheap(h);
	for (i = 0; i < h->size; i++) {
    
    
		huffmantree t =(huffmantree) malloc(sizeof(struct treenode));
		t->left = deletemin(h);
		t->right = deletemin(h);
		t->weight = t->left->weight + t->right->weight;
		insert(h, t);
	}
	t = deletemin(h);
	return t;
}