SameTree.java

/**
 * 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.
 * <p>
 * Accepted.
 */
public class SameTree {

    public boolean isSameTree(TreeNode p, TreeNode q) {
        return p == null && q == null
                || p != null && q != null && p.val == q.val && isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
    }

    public static class TreeNode {

        int val;
        TreeNode left;
        TreeNode right;

        TreeNode(int x) {
            val = x;
        }

    }

}