#define _CRT_SECURE_NO_WARNINGS 1
#include<stdlib.h>
#include<stdio.h>
#define N 30    //叶子结点的最大值
#define M 2*N-1 // 结点总数
typedef struct HTNode
{
	int weight;
	int parent;
	int Lchild;
	int Rchild;
	int flag;
}HTNode,HuffmanTree[M+1];//HuffmanTree[M+1] 0号单元不使用
//初始化
void InitHuffmanTree(HuffmanTree ht, int n)//初始哈夫曼树
{
    //1-n是叶子结点    n+1 - m 是非叶子结点
    //初始化叶子节点
    for (int i = 1; i <= n; i++)
    {
        ht[i].Lchild = 0;
        ht[i].Rchild = 0;
        ht[i].weight = 0;
        ht[i].parent = 0;
        ht[i].flag = 0;
        scanf("%d", &ht[i].weight);//赋值权值
    }

    int m = 2 * n - 1;//总结点数值
    //初始化非叶子节点
    for (int i = n + 1; i <= m; i++)
    {
        ht[i].Lchild = 0;
        ht[i].Rchild = 0;
        ht[i].weight = 0;
        ht[i].parent = 0;
        ht[i].flag = 0;
    }
}
int select(HuffmanTree ht, int n)
{
    int i, temp, min;
    //拿到第一个权值的信息去比较下面
    for (i = 1; i <= n; i++)
    {
        if (ht[i].flag == 0)
        {
            temp = ht[i].weight;//记录权值
            min = i;//记录下标索引
            break;
        }
    }
    for (i = 1; i <= n; i++)
    {
        if (ht[i].flag == 0 && temp > ht[i].weight)//把temp权值小的才进来
        {
            //把更小的权值赋给temp
            temp = ht[i].weight;
            min = i;
        }
    }
    ht[min].flag = 1;//只要这里flga赋为1，找次最小权值的时候就不会重复
    return min;
}
void CreateHuffmanTree(HuffmanTree ht, int n)
{
    //n+1 到 m 之间
    for (int i = n + 1; i <= (2 * n - 1); i++)
    {
        int s1 = select(ht, i - 1);//i-1是相当于是n，意思是把所有叶子结点的总数传到select
        int s2 = select(ht, i - 1);
        ht[i].weight = ht[s1].weight + ht[s2].weight;
        ht[s1].parent = i;
        ht[s2].parent = i;
        ht[i].Lchild = s1;
        ht[i].Rchild = s2;
    }
}
void printHuffmanTree(HuffmanTree ht, int n)
{
    printf("结点  weigh  parent Lchild Rchild\n");
    for (int i = 1; i <= n; i++)
    {
        printf("%d\t%d\t%d\t%d\t%d\n", i, ht[i].weight, ht[i].parent, ht[i].Lchild, ht[i].Rchild);
    }
    printf("\n");
}
void freeHuffmanTree(HuffmanTree ht)
{

}
int main()
{
	HuffmanTree HT;
	int n;//所需的叶子结点数
	printf("请输入初始的叶子结点个数\n");
	scanf("%d", &n);

	printf("请输入%d个叶子结点分别的权值\n", n);
    //初始化
	InitHuffmanTree(HT, n);

    printf("初始哈夫曼树如下\n");
    printHuffmanTree(HT, 2 * n - 1);

    //构造哈夫曼
    CreateHuffmanTree(HT, n);
    printf("构建后的哈夫曼树如下\n");
    printHuffmanTree(HT, 2 * n - 1);

    return 0;
}