Datasets:
Tasks:
Text Generation
Modalities:
Text
Formats:
json
Languages:
English
Size:
< 1K
ArXiv:
Tags:
competitive-programming
code-generation
specification-generation
proof-generation
verification
rust
License:
| use vstd::prelude::*; | |
| fn main() {} | |
| verus! { | |
| pub struct Solution; | |
| impl Solution { | |
| pub closed spec fn is_sequential_digits(n: int) -> bool | |
| decreases n | |
| { | |
| if n < 10 { | |
| 1 <= n && n <= 9 | |
| } else { | |
| let last = n % 10; | |
| let rest = n / 10; | |
| let prev = rest % 10; | |
| 2 <= last && last <= 9 && prev == last - 1 && Self::is_sequential_digits(rest) | |
| } | |
| } | |
| pub fn sequential_digits(low: i32, high: i32) -> (result: Vec<i32>) | |
| requires | |
| 10 <= low <= high <= 1000000000, | |
| ensures | |
| forall|i: int| 0 <= i < result.len() ==> low <= result[i] <= high, | |
| forall|i: int| 0 <= i < result.len() ==> Self::is_sequential_digits( result[i] as int), | |
| forall|i: int, j: int| 0 <= i < j < result.len() ==> result[i] < result[j], | |
| forall|x: int| (low <= x <= high && Self::is_sequential_digits(x)) ==> exists|k: int| 0 <= k < result.len() && result[k] == x as i32, | |
| { | |
| let candidates = [ | |
| 12i32, 23, 34, 45, 56, 67, 78, 89, | |
| 123, 234, 345, 456, 567, 678, 789, | |
| 1234, 2345, 3456, 4567, 5678, 6789, | |
| 12345, 23456, 34567, 45678, 56789, | |
| 123456, 234567, 345678, 456789, | |
| 1234567, 2345678, 3456789, | |
| 12345678, 23456789, | |
| 123456789, | |
| ]; | |
| let mut result: Vec<i32> = Vec::new(); | |
| let mut i = 0; | |
| while i < candidates.len() | |
| { | |
| let x = candidates[i]; | |
| if low <= x && x <= high { | |
| result.push(x); | |
| } | |
| i += 1; | |
| } | |
| result | |
| } | |
| } | |
| } | |