LeetCode OJ Binary Tree Right Side View

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]

.

Credits:

Special thanks to @amrsaqr for adding this problem and creating all test cases.

直接優先右周遊即可，更新最大高度。

class Solution {
public:
	int depth;
	vector<int> ans;
	vector<int> rightSideView(TreeNode * root) {
		depth = -1;
		ans.clear();
		RL(root, 0);
		return ans;
	}
	void RL(TreeNode * now, int nowDepth) {
		if (!now) return;
		if (nowDepth > depth) ans.push_back(now->val), depth = nowDepth;
		RL(now->right, nowDepth + 1);
		RL(now->left, nowDepth + 1);
	}
};