100. Same Tree

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.

 

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)

            return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);

        return false;

    }

}