辅助类BinaryTreeNodeIndex

(用index索引代替指针）

template<typename T>
class BinaryTreeNodeIndex
{
public:T key;int left;int right;int parent;
public:BinaryTreeNodeIndex(){}BinaryTreeNodeIndex(const T key,int parent = -1,int left = -1,int right = -1):key(key),parent(parent),left(left),right(right){}
};