#include<iostream>
#include<algorithm>
using namespace std;

struct Tree
{
	double data;
	Tree *lChild, *rChild;
	Tree *fater;
};
/*创建哈夫曼树*/
void buildHFM(Tree *t[]);
/*获取编码*/
void getWay(Tree *node[], int n);
void getFat(Tree *root);

int cod[20] = { 0 };//存储哈夫曼树编码
int a, b;//跟踪数组的下标，做删除和增加操作
int k;//记录编码的长度
int main()
{
	int n;
	cout << "请输入结点的个数：";
	cin >> n;
	a = 0;
	b = n - 1;
	Tree **node = new Tree*[n];
	Tree **t = new Tree*[2*n];
	cout << "请输入结点的权值：" << endl;
	//对结点的属性进行初始化
	for (int i = 0; i < n; i++)
	{
		node[i] = t[i] = new Tree;
		cin >> t[i]->data;
		t[i]->fater = t[i]->lChild = t[i]->rChild = NULL;
	}
	//进行第一次排序
	sort(t, t + n, [](Tree *a, Tree *b) {return a->data < b->data; });
	//创建哈夫曼树
	buildHFM(t);
	//获取编码
	cout <<"编码为分别为：" << endl;
	getWay(node, n);
	system("pause");
	return 0;
}

void buildHFM(Tree *t[])
{

	double sum;
	while (a < b)
	{
		sum = t[a]->data + t[a + 1]->data;
		b++;//b加1
		//加入新结点并刷新其属性
		t[b] = new Tree;
		t[b]->data = sum;
		if (t[a]->data > t[a + 1]->data)
		{
			t[b]->lChild = t[a];
			t[b]->rChild = t[a + 1];
			t[b]->fater = NULL;
		}
		else
		{
			t[b]->rChild = t[a];
			t[b]->lChild = t[a + 1];
			t[b]->fater = NULL;
		}
		//刷新两个子结点的父结点
		t[a]->fater = t[a + 1]->fater = t[b];
		a += 2;//a往后移两位

		int index = b;
		int index2 = b-1;
		//重新排序序列
		while (t[index]->data <= t[index2]->data)
		{
			swap(t[index--], t[index2--]);
			if (index2 < a)//小于新初始结点，退出
				break;
		}
	}
}

void getWay(Tree *node[], int n)
{
	int i = 0;
	while (i < n)
	{
		k = 0;//编码长度初始化为0
		getFat(node[i++]);//依次获取父结点
		//输出编码
		cout << node[i - 1]->data << " ：";
		for (int j = k - 1; j >= 0; j--)
		{
			cout << cod[j];
		}
		cout << endl;
	}
}

void getFat(Tree *root)
{
	if (root->fater == NULL)
		return;
	Tree *T = root->fater;
	if (T->lChild == root)
		cod[k++] = 0;
	else
		cod[k++] = 1;
	getFat(T);
}