C++:
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
vector<double> averageOfLevels(TreeNode* root) {
vector<double> res;
queue<TreeNode*> q;
q.push(root);
double sum,avg;
while(!q.empty())
{
int num=q.size();
sum=0;
for(int i=0;i<num;i++)
{
TreeNode* temp=q.front();
sum+=temp->val;
q.pop();
if(temp->left!=NULL)
q.push(temp->left);
if(temp->right!=NULL)
q.push(temp->right);
}
avg=sum/num;
res.push_back(avg);
}
return res;
}
};
def averageOfLevels(self, root):
info = []
def dfs(node, depth = 0):
if node:
if len(info) <= depth:
info.append([0, 0])
info[depth][0] += node.val
info[depth][1] += 1
dfs(node.left, depth + 1)
dfs(node.right, depth + 1)
dfs(root)
return [s/float(c) for s, c in info]
Average of Levels in Binary Tree
原文:http://www.cnblogs.com/xlqtlhx/p/7814236.html