
public class _100SameTree {
	public boolean isSameTree(TreeNode p, TreeNode q) {
        if (p == null && q == null) return true;
        else if (p == null && q != null) return false;
        else if (p != null && q == null) return false;
        else {
        	if (p.val == q.val) return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
        	else return false;
        }
    }
	
	public class TreeNode {
		int val;
		TreeNode left;
		TreeNode right;
		TreeNode(int x) { val = x; }
	}
}

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