Same Tree — Structural and Value Comparison

# Python
def isSameTree(p, q):
    if not p and not q: return True
    if not p or not q: return False
    return p.val == q.val and isSameTree(p.left,q.left) and isSameTree(p.right,q.right)

// Java
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);
}