Binary Trees

100. Same Tree 📗

Problem

Given the roots of two binary trees p and q, write a function to check if they are the same or not.

Two binary trees are considered the same if they are structurally identical, and the nodes have the same value.

Solution

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def isSameTree(self, p: Optional[TreeNode], q: Optional[TreeNode]) -> bool:
        if p is None and q is None:
            return True
        elif p is None or q is None:
            return False
        else:
            if p.val != q.val:
                return False
            else:
                return self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)

// Definition for a binary tree node.
// #[derive(Debug, PartialEq, Eq)]
// pub struct TreeNode {
//   pub val: i32,
//   pub left: Option<Rc<RefCell<TreeNode>>>,
//   pub right: Option<Rc<RefCell<TreeNode>>>,
// }
// 
// impl TreeNode {
//   #[inline]
//   pub fn new(val: i32) -> Self {
//     TreeNode {
//       val,
//       left: None,
//       right: None
//     }
//   }
// }
use std::rc::Rc;
use std::cell::RefCell;
impl Solution {
    pub fn is_same_tree(p: Option<Rc<RefCell<TreeNode>>>, q: Option<Rc<RefCell<TreeNode>>>) -> bool {
        match (p, q) {
            (None, None) => true,
            (Some(p_node), Some(q_node)) => {
                let p_node = p_node.borrow();
                let q_node = q_node.borrow();
                p_node.val == q_node.val &&
                Solution::is_same_tree(p_node.left.clone(), q_node.left.clone()) &&
                Solution::is_same_tree(p_node.right.clone(), q_node.right.clone())
            }
            _ => false,
        }
    }
}