方法一,参考 http://blog.youkuaiyun.com/forestlight/article/details/6575507
- template<typename T>
- int DepthTree(BSTreeNode<T> *pbs)
- {
- if (pbs==NULL)
- return 0;
- else
- {
- int leftLength=DepthTree(pbs->left);
- int rigthLength=DepthTree(pbs->right);
- return 1+(leftLength>rigthLength ? leftLength:rigthLength);
- }
- }
- template<typename T>
- bool isBalanceTree(BSTreeNode<T> *pbs)
- {
- if (pbs==NULL)
- {
- return true;
- }
- int depthLeft=DepthTree(pbs->left);
- int depthRight=DepthTree(pbs->right);
- if (abs(depthLeft-depthRight)>1)
- return false;
- else
- return isBalanceTree(pbs->left) && isBalanceTree(pbs->right);
- }
方法一用的是线序遍历的思想, 缺点是,重复计算了多次子树的深度
方法二用的是后序遍历的思想,免去了对子树的重复计算
template<typename T>
bool isBalanceTree(BSTreeNode<T> *pbs, int &curLen)
{
if (pbs==NULL)
{
return true;
}
int leftLen;
int rightLen;
bool isLeftBalance;
bool isRightBalance;
leftLen = rightLen = 0;
isLeftBalance = isRightBalance = false;
isLeftBalance = isBalanceTree(pbs->left, leftLen);
isRightBalance = isBalanceTree(pbs->right, rightLen);
curLen = leftLen >= rightLen ? leftLen+1 : rightLen+1;
if (isLeftBalance == true && isRightBalance == true)
{
if (abs(depthLeft-depthRight) <= 1)
{
return true;
}
}
return false;
}