树——哈夫曼树

哈夫曼树的构造：

    从给定的n个数中,选两次最小值，将这两个数的和作为结点的权值，并将这两个数分别置为结点的左右孩子，该结点置为两个数的父亲结点.并将该结点放入所给的n个数中，重复该过程n-1次。

#include <iostream>
#include<cstdio>
#include<iomanip>
using namespace std;

typedef struct HuffmanTree{
    int weight;
    int parent,leftchild,rightchild;
}HuffmanTree,*PHuffmanTree;

void Select(PHuffmanTree &ph,int s,int &s1,int &s2){
    s1=-1;
    for(int i=1;i<=s;i++){
        if(!ph[i].parent&&s1==-1){
            s1=i;
            continue;
        }
        else if(!ph[i].parent&&s1!=-1){
            s2=i;
            break;
        }
    }
    for(int i=s2;i<=s;i++){
        if(!ph[i].parent){
            if(ph[i].weight<ph[s1].weight){
                s2=s1;
                s1=i;
            }
            else if(ph[i].weight<ph[s2].weight)
                s2=i;
        }
    }
}

void CreateHuffmanTree(PHuffmanTree &ph,int n){
    int s1,s2,x,j=0;
    ph=new HuffmanTree[n+1];
    for(int i=1;i<=2*n-1;i++){
        ph[i].parent=0;
        ph[i].leftchild=0;
        ph[i].rightchild=0;
    }
   for(int i=1;i<=8;i++)
    scanf("%d",&ph[i].weight);
    cout<<endl;

    for(int i=n+1;i<=2*n-1;i++){
        Select(ph,i-1,s1,s2);
        ph[s1].parent=i;    ph[s2].parent=i;
        ph[i].leftchild=s1; ph[i].rightchild=s2;
        ph[i].weight=ph[s1].weight+ph[s2].weight;
    }
}

void ShowHuffmanTree(PHuffmanTree ph,int n){
    for(int i=1;i<=2*n-1;i++){
        cout<<ph[i].weight<<" parent:"<<ph[i].parent<<" leftchild:"<<ph[i].leftchild;
        cout<<" rightchild:"<<ph[i].rightchild<<endl;
    }
}

int main(){
        int n;
        while(cin>>n){
             PHuffmanTree ph;
             CreateHuffmanTree(ph,n);
             ShowHuffmanTree(ph,n);
        }
}