Codeforces Round 735 (Div. 2) |
---|
Finished |
You are given two integers $$$n$$$ and $$$m$$$. Find the $$$\operatorname{MEX}$$$ of the sequence $$$n \oplus 0, n \oplus 1, \ldots, n \oplus m$$$. Here, $$$\oplus$$$ is the bitwise XOR operator.
$$$\operatorname{MEX}$$$ of the sequence of non-negative integers is the smallest non-negative integer that doesn't appear in this sequence. For example, $$$\operatorname{MEX}(0, 1, 2, 4) = 3$$$, and $$$\operatorname{MEX}(1, 2021) = 0$$$.
The first line contains a single integer $$$t$$$ ($$$1 \le t \le 30\,000$$$) — the number of test cases.
The first and only line of each test case contains two integers $$$n$$$ and $$$m$$$ ($$$0 \le n, m \le 10^9$$$).
For each test case, print a single integer — the answer to the problem.
5 3 5 4 6 3 2 69 696 123456 654321
4 3 0 640 530866
In the first test case, the sequence is $$$3 \oplus 0, 3 \oplus 1, 3 \oplus 2, 3 \oplus 3, 3 \oplus 4, 3 \oplus 5$$$, or $$$3, 2, 1, 0, 7, 6$$$. The smallest non-negative integer which isn't present in the sequence i. e. the $$$\operatorname{MEX}$$$ of the sequence is $$$4$$$.
In the second test case, the sequence is $$$4 \oplus 0, 4 \oplus 1, 4 \oplus 2, 4 \oplus 3, 4 \oplus 4, 4 \oplus 5, 4 \oplus 6$$$, or $$$4, 5, 6, 7, 0, 1, 2$$$. The smallest non-negative integer which isn't present in the sequence i. e. the $$$\operatorname{MEX}$$$ of the sequence is $$$3$$$.
In the third test case, the sequence is $$$3 \oplus 0, 3 \oplus 1, 3 \oplus 2$$$, or $$$3, 2, 1$$$. The smallest non-negative integer which isn't present in the sequence i. e. the $$$\operatorname{MEX}$$$ of the sequence is $$$0$$$.
Name |
---|