Huffman树的构建和WPL的计算

#include 
using namespace std;
struct hufftree{
	int weight;
	int lchild,rchild,parent;
}huff[10001];
int n,a[1001];
int i1,i2;
int sum=0;
bool cmp(hufftree a,hufftree b){
	return a.weight<b.weight;
}
void select(int x){
	sort(huff,huff+x,cmp);
	for(int i=0;i<x;i++){
		if(huff[i].parent==-1){
			i1=i;
			i2=i+1;
			break;
		}
	}
}
void CreateHuffmanTree(){
	for(int i=0;i<2*n-1;i++){
		huff[i].parent=-1;
		huff[i].lchild=-1;
		huff[i].rchild=-1; 
	} 
	for(int i=0;i<n;i++)
		huff[i].weight=a[i];
	for(int i=n;i<2*n-1;i++){
		select(i);
		huff[i].weight=huff[i1].weight+huff[i2].weight;
		huff[i].lchild=i1;
		huff[i].rchild=i2;
		huff[i1].parent=i;
		huff[i2].parent=i;
		sum+=huff[i].weight;
	}
}
int main(){
	cin>>n;
	for(int i=0;i<n;i++)
		cin>>a[i];
	CreateHuffmanTree();
	cout<<"HuffmanTree WPL is "<<sum; 
	return 0;
}