Binary Tree Right Side View
Binary Tree Right Side View
题目
Given a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bottom.
For example:
Given the following binary tree,
1 <---
/ \
2 3 <---
\ \
5 4 <---
You should return [1, 3, 4].
思路
层次遍历
解题
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29/**
* 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<int> rightSideView(TreeNode* root) {
vector<int> result;
levelOrder(root,1,result);
return result;
}
void levelOrder(TreeNode* root,int level,vector<int>& result){
if(!root)
return;
if(level>result.size())
result.push_back(0);
result[level-1]=root->val;
levelOrder(root->left,level+1,result);
levelOrder(root->right,level+1,result);
}
};
Python版1
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23# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution:
# @param {TreeNode} root
# @return {integer[]}
def rightSideView(self, root):
result=[]
self.levelOrder(root,1,result)
return result
def levelOrder(self,root,level,result):
if not root:
return
if level>len(result):
result.append(0)
result[level-1]=root.val
self.levelOrder(root.left,level+1,result)
self.levelOrder(root.right,level+1,result)
