[leetcode 222]Count Complete Tree Nodes

Given a complete binary tree, count the number of nodes.

Definition of a complete binary tree from Wikipedia:

In a complete binary tree every level, except possibly the last, is completely filled, and all nodes in the last level are as far left as possible. It can have between 1 and 2hnodes
inclusive at the last level h.

计算完全二叉树的所有节点的个数。

暴力超时，首先判断该树是否为满完全二叉树，是的话性质求解，否则暴力求解

AC代码：

class Solution {
public:
int countNodes(TreeNode* root) {
if(root==NULL)
return 0;
int l=1;
int r=1;
TreeNode *tempLeft=root;
TreeNode *tempRight=root;
while(tempLeft)
{
tempLeft=tempLeft->left;
++l;
}
while(tempRight)
{
tempRight=tempRight->right;
++r;
}
if(l==r)
return 1<<l-1;
else
return countNodes(root->left)+countNodes(root->right)+1;
}
};

其他Leetcode题目AC代码：https://github.com/PoughER/leetcode