Trees : Maximum Depth of Binary Tree

maxDepth.go

/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */

type t struct {
    n *TreeNode
    d int
}
func maxDepth(root *TreeNode) int {
    if root == nil {
        return 0
    }
    
    stack := []*t{
        &t{
            n : root,
            d : 1,
        },
    }
    
    depth := 0
    for len(stack) > 0 {
        s := stack[len(stack)-1]
        stack = stack[:len(stack)-1]
        n := s.n
        nDepth := s.d
        
        if nDepth > depth {
            depth = nDepth
        }
        
        if n.Right != nil {
            stack = append(stack, &t{
                n : n.Right,
                d:nDepth+1,
            })
        }
        
        if n.Left != nil {
            stack = append(stack, &t{
                n : n.Left,
                d : nDepth+1,
            })
        }
    }
    
    return depth
}