[LeetCode 100] Same Tree

문제 바로가기

Description

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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.

Example 1

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

Example 2

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

Example 3

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

Constraints

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• The number of nodes in both trees is in the range [0, 100].
• -10^4 <= Node.val <= 10^4

Code

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내 제출

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/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        if (p == q) return true;
        if (p == null || q == null || p.val != q.val) return false;
        return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
    }
}

Runtime	Memory
0 ms	40.9 MB

다른 풀이

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/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {

        if(p==null && q==null)
        {
            return true;
        }
        if(p==null || q==null)
        {
            return false;
        }

         if((p.val == q.val) &&  isSameTree(p.left, q.left) &&  isSameTree(p.right, q.right))
         {
            return true;
         }

         else
         {
            return false;
         }
    }
}

Reference

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• https://github.com/doocs/leetcode/blob/main/solution/0100-0199/0100.Same%20Tree/Solution.java