LeetCode-in-Go
199. Binary Tree Right Side View
Medium
Given the root of 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.
Example 1:
Input: root = [1,2,3,null,5,null,4]
Output: [1,3,4]
Example 2:
Input: root = [1,null,3]
Output: [1,3]
Example 3:
Input: root = []
Output: []
Constraints:
- The number of nodes in the tree is in the range
[0, 100]. -100 <= Node.val <= 100
Solution
/**
* Definition for a binary tree node.
* type TreeNode struct {
* Val int
* Left *TreeNode
* Right *TreeNode
* }
*/
func rightSideView(root *TreeNode) []int {
var list []int
recurse(root, 0, &list)
return list
}
func recurse(node *TreeNode, level int, list *[]int) {
if node != nil {
if len(*list) < level+1 {
*list = append(*list, node.Val)
}
recurse(node.Right, level+1, list)
recurse(node.Left, level+1, list)
}
}