P13996 【MX-X19-T5】「FeOI Round 4.5」Angel's Clover
Background
[Angel's Clover - DIVELA / Kagamine Len / MORE MORE JUMP!](https://www.bilibili.com/video/BV1oh2PYcEiW)
> 全身全霊!MORE MORE JUMP!!
Description
Minori has a $01$ sequence $s$, initially $s = [0, 1]$. The indices of this sequence start from $0$.
For a $01$ sequence $s = [s_0, \ldots, s_{\lvert s \rvert - 1}]$ with indices starting from $0$, define the new $01$ sequence $t = f(s)$ obtained after one $f$-transformation as:
- Initially, $t$ is empty.
- For each $i = 0, \ldots, \lvert s \rvert - 1$, append to the end of $t$:
- $1$ copy of $i \bmod 2$ (if $s_i = 0$);
- $3$ copies of $i \bmod 2$ (if $s_i = 1$).
- The indices of $t$ also start from $0$.
For example, $f([0, 1]) = [0, 1, 1, 1]$, and $f([0, 1, 1, 1]) = [0, 1, 1, 1, 0, 0, 0, 1, 1, 1]$.
For a non-negative integer $x$, define the notation $f^x(s)$ as the sequence obtained by applying the $f$-transformation to $s$ consecutively $x$ times.
Minori will give you $q$ queries. Each query provides two non-negative integers $x, r$, and asks for the value of the element at index $r$ in $f^x(s)$. If the length of $f^x(s)$ is $\le r$, meaning there is no element at index $r$, you must report that.
Input Format
The first line contains a positive integer $q$.
The next $q$ lines each contain two non-negative integers $x, r$.
Output Format
For each query, output one line. If an element at index $r$ exists, output a non-negative integer representing its value; otherwise, output `-1`.
Explanation/Hint
**【Sample Explanation】**
The initial sequence is $[0,1]$.
After one transformation, the sequence becomes $[0,1,1,1]$.
After two transformations, the sequence becomes $[0,1,1,1,0,0,0,1,1,1]$.
**【Data Range】**
**The test cases are not equally weighted. See the score column for details.**
| Test Case ID | $x \le$ | $q \le$ | Special Properties | Score |
|:------------:|:-----------:|:---------:|:------------------:|:-----:|
| $1$ | $3$ | $10^4$ | None | $12$ |
| $2$ | $10$ | $20$ | None | $19$ |
| $3$ | $10^{18}$ | $10$ | No answer is $0$ | $19$ |
| $4$ | $10^{18}$ | $20$ | $x\ge 10^{12}$ | $10$ |
| $5$ | $10^{18}$ | $10^4$ | None | $40$ |
For all test cases, $1\le q\le 10^4$, $0\le x,r\le 10^{18}$.
*Translated by DeepSeek V3.1*