二叉樹的幾道典型例題
阿新 • • 發佈：2018-12-25
1.求二叉樹的高度
int _GetTreeHight(Node<T>* pRoot)
{
if(pRoot==NULL)
return 0;
if(pRoot->_pLeft==NULL&&pRoot->_pRight==NULL)
return 1;
int left=_GetTreeHight(pRoot->_pLeft)+1;
int right=_GetTreeHight(pRoot->_pRight)+1;
return left>right?left:right;
}3.判斷一個數據是否在一棵二叉樹中int _LeafNodeNum(Node<T>* pRoot) { if(pRoot==NULL) return 0; if(pRoot->_pLeft==NULL&&pRoot->_pRight==NULL) return 1; int left=_LeafNodeNum(pRoot->_pLeft); int right=_LeafNodeNum(pRoot->_pRight); return left+right; }
Node<T>* _Find(Node<T>* pRoot,const T& data)
{
if(pRoot==NULL)
return NULL;
if(pRoot->_value==data)
return pRoot;
Node<T>* pcur=_Find(pRoot->_pLeft,data);
if(pcur)
return pcur;
return _Find(pRoot->_pRight,data);
}4.求二叉樹中兩個結點的最近公共祖先結點
5.查詢一個節點的雙親節點bool GetWay(Node<T>* pRoot,Node<T>* N,vector<Node<T>*>& v,size_t index) { if(pRoot==NULL) return false; v.push_back(pRoot); if(pRoot==N) return true; pRoot=v.back(); if(GetWay(pRoot->_pLeft,N,v,index+1)) return true; v.pop_back(); pRoot=v.back(); return GetWay(pRoot->_pRight,N,v,index+1); } Node<T>* _LastAncestorNode(Node<T>* pRoot,Node<T>* N1,Node<T>* N2) { if(pRoot==NULL||(pRoot->_pLeft==NULL&&pRoot->_pRight==NULL)) return NULL; vector<Node<T>*> v1; vector<Node<T>*> v2; if(GetWay(pRoot,N1,v1,0)&&GetWay(pRoot,N2,v2,0)) { for(size_t i=v1.size();i>0;--i) { for(size_t j=v2.size();j>0;--j) { if(v1[i-1]==v2[j-1]) return v1[i-1]; } } } return NULL; }
Node<T>* _FindParent(Node<T>* pRoot,Node<T>* pRet) { if(pRoot==NULL||pRet==pRoot) return NULL; if(pRoot->_pLeft==pRet||pRoot->_pRight==pRet) { return pRoot; } Node<T>* pcur=_FindParent(pRoot->_pLeft,pRet); if(pcur) return pcur; return _FindParent(pRoot->_pRight,pRet); }
6.求二叉樹中最遠的兩個結點之間的距離
int _DistanceOfNodes(Node<T>* pRoot)
{
if(pRoot==NULL)
return 0;
int left=_GetTreeHight(pRoot->_pLeft);
int right=_GetTreeHight(pRoot->_pRight);
return left+right;
}7.判斷一棵二叉樹是否是完全二叉樹
bool _IsCompleteBinaryTree(Node<T>* pRoot)
{
if(pRoot==NULL)
return false;
queue<Node<T>*> q;
q.push(pRoot);
while((pRoot=q.front())!=NULL)
{
q.push(pRoot->_pLeft);
q.push(pRoot->_pRight);
q.pop();
}
while(!q.empty()&&(pRoot=q.front())==NULL)
{
q.pop();
}
if(!q.empty())
return false;
return true;
}8.求二叉樹的映象
BinaryTree<T> ImageBinaryTree()
{
BinaryTree<T> bt;
bt._pRoot=CopyTree(_pRoot);
_ImageBinaryTree(bt._pRoot);
return bt;
}
void _ImageBinaryTree(Node<T>* pRoot)
{
Node<T>* pcur=pRoot;
if(pcur==NULL||(pcur->_pLeft==NULL&&pcur->_pRight==NULL))
return ;
swap(pcur->_pLeft,pcur->_pRight);
_ImageBinaryTree(pcur->_pLeft);
_ImageBinaryTree(pcur->_pRight);
}