codeforces#P1734F. Zeros and Ones
Zeros and Ones
Description
Let $S$ be the Thue-Morse sequence. In other words, $S$ is the $0$-indexed binary string with infinite length that can be constructed as follows:
- Initially, let $S$ be "0".
- Then, we perform the following operation infinitely many times: concatenate $S$ with a copy of itself with flipped bits.
For example, here are the first four iterations:
Iteration $S$ before iteration $S$ before iteration with flipped bits Concatenated $S$ 1 0 1 01 2 01 10 0110 3 0110 1001 01101001 4 01101001 10010110 0110100110010110 $\ldots$ $\ldots$ $\ldots$ $\ldots$
You are given two positive integers $n$ and $m$. Find the number of positions where the strings $S_0 S_1 \ldots S_{m-1}$ and $S_n S_{n + 1} \ldots S_{n + m - 1}$ are different.
Each test contains multiple test cases. The first line of the input contains a single integer $t$ ($1 \le t \le 100$) — the number of test cases. The description of the test cases follows.
The first and only line of each test case contains two positive integers, $n$ and $m$ respectively ($1 \leq n,m \leq 10^{18}$).
For each testcase, output a non-negative integer — the Hamming distance between the two required strings.
Input
Each test contains multiple test cases. The first line of the input contains a single integer $t$ ($1 \le t \le 100$) — the number of test cases. The description of the test cases follows.
The first and only line of each test case contains two positive integers, $n$ and $m$ respectively ($1 \leq n,m \leq 10^{18}$).
Output
For each testcase, output a non-negative integer — the Hamming distance between the two required strings.
6
1 1
5 10
34 211
73 34
19124639 56348772
12073412269 96221437021
1
6
95
20
28208137
48102976088
Note
The string $S$ is equal to 0110100110010110....
In the first test case, $S_0$ is "0", and $S_1$ is "1". The Hamming distance between the two strings is $1$.
In the second test case, $S_0 S_1 \ldots S_9$ is "0110100110", and $S_5 S_6 \ldots S_{14}$ is "0011001011". The Hamming distance between the two strings is $6$.