/*自己編寫的C語言的赫夫曼樹*/

#include<stdio.h>
#include<string.h>
#define HUFFSIZE 8
#define TOTALSIZE (2*HUFFSIZE) 
typedef struct 
{
	int weight;
	int parent;
	int leftchild;
	int rightchild;
}HuffNode;
typedef HuffNode HuffTree[TOTALSIZE];

typedef struct
{
	char ch;
	char code[HUFFSIZE + 1];
}HuffCoding;
typedef HuffCoding HuffCode[HUFFSIZE + 1 ];

void Init_HuffTree(HuffTree ht, int a[])
{
	memset(ht, 0, sizeof(HuffTree));
	for (int i = 1; i < HUFFSIZE + 1; ++i)
	{
		ht[i].weight = a[i - 1];
	}
}

void Print_Hufftree(HuffTree ht)  
{
	printf("%5s   %5s    %5s    %5s    %5s\n"," ID","weight","parent","leftchild","rightchild");
	for (int i = 1; i < TOTALSIZE ; ++i)
	{
		printf("%5d    %5d    %5d    %5d    %5d\n", i, ht[i].weight, ht[i].parent, ht[i].leftchild, ht[i].rightchild);

	}
}

int find_min1(HuffTree ht,int n)
{
	int i = 1;
	while ((i < n)&&(ht[i].parent != 0))++i;
	for (int j = 1 + i; j < n; ++j)
	{
		if((ht[j].parent==0)&&(ht[i].weight>ht[j].weight))
		{
			i = j;
		}
	}
	return i;
}

void find_min2(HuffTree ht, int n, int *min2)
{
	int min1;
	min1 = find_min1(ht, n);
	int i = 1;
	while (((i < n )&&(ht[i].parent != 0)) || (i==min1))++i;
	for (int j = 1 + i; j < n; ++j)
	{
		if ((ht[j].parent == 0) && (ht[i].weight > ht[j].weight) &&( j!=min1))
		{
			i = j;
		}
	}
	*min2 = i;
}

void CreateHuffTree(HuffTree ht)
{
	int left, right;
	int k = HUFFSIZE + 1;
	while (k < TOTALSIZE)
	{
		left=find_min1(ht, k);
		find_min2(ht, k, &right);
		ht[k].weight = ht[left].weight + ht[right].weight;
		ht[k].leftchild = left;
		ht[k].rightchild = right;
		ht[left].parent = k;
		ht[right].parent = k;
		++k;
	}
}

void Init_HuffCode(HuffCode hc,char br[])
{
	memset(hc,0,sizeof(HuffCode));
    for (int i = 1; i < HUFFSIZE + 1; ++i)
   {
		hc[i].ch = br[i - 1];
		hc[i].code[0] = '\0';
	}
}

void CreateHuffCode(HuffTree ht, HuffCode hc)
{
	char code[HUFFSIZE + 1];
	int child, parent;
	for (int i = 1; i < HUFFSIZE + 1; ++i)
	{
		int k=HUFFSIZE;
		code[k] = '\0';
		child = i;
		while ((parent=ht[child].parent) != 0)
		{
			code[--k] = ht[parent].leftchild == child ? '0' : '1';
			child = parent;
		}
		strcpy_s(hc[i].code, &code[k]);
	}
}
void Print_Code(HuffCode hc)
{
	for (int i = 1; i < HUFFSIZE + 1; ++i)
	{
		printf("%c的赫夫曼碼:%s\n", hc[i].ch, hc[i].code);
	}
}
int main()
{
	HuffTree ht;
	HuffCode hc;
	int a[] = { 1,2,23,4,5,6,7,8 };
	char br[] = { 'a','b','c','d','e','f','g','h' };
	Init_HuffTree(ht, a);
	Print_Hufftree(ht);
	CreateHuffTree(ht);
	Print_Hufftree(ht);
	Init_HuffCode(hc,br);
	CreateHuffCode(ht, hc);
	Print_Code(hc);
	getchar();
	return 0;
}