100.Same Tree

tags: Easy,Tree,DFS,BFS,Binary Tree

100. Same Tree

題目描述

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.

範例

Example 1:

Input: p = [1,2,3], q = [1,2,3]
Output: true

Example 2:

Input: p = [1,2], q = [1,null,2]
Output: false

Example 3:

Input: p = [1,2,1], q = [1,1,2]
Output: false

Constraints:

• The number of nodes in both trees is in the range [0, 100].
• -10⁴ <= Node.val <= 10⁴

解答

Javascript

function isSameTree(p, q) {
  if (p === null && q === null) return true;
  if (p === null || q === null) return false;
  if (p.val !== q.val) return false;
  return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
}

Marsgoat Jan 10, 2023

Python

class Solution:
    def isSameTree(self, p: Optional[TreeNode], q: Optional[TreeNode]) -> bool:
        if not p and not q: return True
        if not p or not q: return False
        return p.val == q.val and self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)

Ron ChenTue, Jan 10, 2023

分享討論區中發現的一行解法

def isSameTree(self, p, q):
    return p and q and p.val == q.val and all(map(self.isSameTree, (p.left, p.right), (q.left, q.right))) or p is q

c#

public class Solution {
    public bool IsSameTree(TreeNode p, TreeNode q) {
        if (p == null && q == null) return true;
        if (p == null || q == null) return false;
        if (p.val != q.val) return false;
        return IsSameTree(p.left, q.left) && IsSameTree(p.right, q.right);
    }
}

JimTue, Jan 10, 2023

Reference

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