Strange Function
English
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Contribute a translation- Time limit
- 2000 ms
- Memory limit
- 256 MB
- Submissions
- 0
- Correct
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- Solved by
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- AC rate
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Statement
For all positive integers $x$, the function $f(x)$ is defined as follows:
- If $x$ has any digits that aren't $0$ or $1$, for each digit of $x$, set it to $1$ if it is odd or $0$ otherwise, and return $x$.
- Otherwise, return $x-1$.
Given a value of $x$ ($1 \leq x < 10^{2\cdot 10^5}$), find how many times $f$ needs to be applied to $x$ until $x$ reaches $0$. As this number might be very large, output its remainder when divided by $10^9+7$.
Input
The first line contains $T$ ($1\le T\le 10^5$), the number of independent tests.
The next $T$ lines each contain a positive integer $x$ consisting solely of the digits 0-9, with no leading zeros.
It is guaranteed that the total number of digits in all input integers does not exceed $10^6$.
Scoring
- Inputs 3-5: $T\le 2000$, $x< 10^{9}$
- Inputs 6-7: $x<10^{18}$
- Inputs 8-9: $x<10^{60}$
- Inputs 10-12: No additional constraints.
Output
For each test case, output the remainder of the number of times when divided by $10^9+7$ on a separate line.
Examples
2 24680 210
1 4
1 1234567890123456789012345678901234567890
511620083
Notes
First test: $x$ becomes zero after one operation.
Second test: $f(x)=10, f^2(x)=9, f^3(x)=1, f^4(x)=0$
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