Question :
Given two binary trees, write a function to check if they are equal or not.
Two binary trees are considered equal if they are structurally identical and the nodes have the same value.
1 | <b>Solution</b> |
Approach 1 :
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 | /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public 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!=null && q==null){return false;} if(p.val==q.val){ if(isSameTree(p.left,q.left) && isSameTree(p.right,q.right)){ return true; } else{ return false; } } else{ return false; } } } |
Optimized Code:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { public boolean isSameTree(TreeNode p, TreeNode q) { if(p == null && q == null) return true; if(p == null || q == null) return false; return (p.val == q.val) && isSameTree(p.left, q.left) && isSameTree(p.right, q.right); } } |
