Method isSameTree

Java/Same-Tree.java:19–40

(TreeNode p, TreeNode q)

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

				return left && right;
			}
		}
	}
}