https://leetcode.com/problems/same-tree/

    1. /**
    2.  * Definition for a binary tree node.
    3.  * type TreeNode struct {
    4.  *     Val int
    5.  *     Left *TreeNode
    6.  *     Right *TreeNode
    7.  * }
    8.  */
    9. func isSameTree(p *TreeNode, q *TreeNode) bool {
    10.     if p == nil && q == nil {
    11.         return true
    12.     }
    14.     if p == nil || q == nil {
    15.         return false
    16.     }
    18.     return (p.Val == q.Val) && isSameTree(p.Left, q.Left) && isSameTree(p.Right, q.Right)
    19. }