Q4.8

#include <iostream>
#include <queue>
#include <vector>
using namespace std;

const int maxn = 100;

struct Node
{
	int data;
	Node *lchild, *rchild, *parent;
};

Node *head, node[maxn];
int cnt = 0;

void Init()
{
	head = NULL;
	memset(node, '\0', sizeof(node));
}

void miniTree(Node* &head, Node *parent, int a[], int lower, int upper)
{
	if(lower <= upper)
	{
		int mid = (lower + upper) >> 1;
		node[cnt].data = a[mid];
		node[cnt].parent = parent;
		head = &node[cnt++];   //key
		miniTree(head->lchild, head, a, lower, mid - 1);
		miniTree(head->rchild, head, a, mid + 1, upper);
	}
}

vector<Node*> v;
int nn = 0;

void print()
{
	cout << ++nn << "list: ";
	Node *t;
	for (vector<Node*>::iterator iter = v.begin(); iter != v.end(); ++iter)
	{
		t = *iter;
		cout << t->data << " ";
	}
	cout << endl;
}

void dfs(Node *head, int val)
{	
	int left = val - head->data;
	if(left == 0)
	{
		print();
		return;
	}
	else if(left < 0)
	{
		return;	
	}
	else
	{
		if(head->parent)
		{
			v.push_back(head->parent);
			dfs(head->parent, left);
			v.pop_back();
		}
			
		if(head->lchild)
		{
			v.push_back(head->lchild);
			dfs(head->lchild, left);
			v.pop_back();
		}
			
		if(head->rchild)
		{
			v.push_back(head->rchild);
			dfs(head->rchild, left);
			v.pop_back();
		}
	}		
}


int main(void)
{
	Init();
	int a[] = {
		1, 2, 3, 4, 5, 6, 7, 8, 9, 10
	};
	int len = sizeof(a) / sizeof(int);
	miniTree(head, NULL, a, 0, len - 1);

	for (int i = 0; i < len; ++i)
	{
		v.push_back(&node[i]);
		dfs(&node[i], 5);
		
		v.clear();
	}
	
	return 0;
}