45 lines
1.1 KiB
Rust
45 lines
1.1 KiB
Rust
use std::{iter::Rev, ops::RangeInclusive};
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pub fn split_from<T>(min: T, max: T, x: T) -> Vec<Vec<T>>
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where
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T: num::Integer + Copy,
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RangeInclusive<T>: Iterator<Item = T> + DoubleEndedIterator,
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Rev<RangeInclusive<T>>: Iterator<Item = T>,
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{
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// check that x is in range
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if min > x || x > max {
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return Vec::new();
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}
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let mut output: Vec<Vec<T>> = Vec::with_capacity(2);
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if x > min + T::one() {
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let x_lower = x - T::one();
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output.push((min..=x_lower).rev().collect());
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}
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if x + T::one() < max {
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output.push(((x + T::one())..=max).collect());
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}
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output
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}
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#[cfg(test)]
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mod test {
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use super::*;
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#[test]
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fn split_test() {
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assert_eq!(split_from(0, 6, 2), vec![vec![1, 0], vec![3, 4, 5, 6]]);
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assert_eq!(split_from(0, 6, 0), vec![vec![1, 2, 3, 4, 5, 6]]);
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assert_eq!(split_from(0, 6, 6), vec![vec![5, 4, 3, 2, 1, 0]]);
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// test out-of-bounds and also generics
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assert_eq!(
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split_from::<i16>(-1i16, 4i16, 10i16),
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Vec::<Vec<i16>>::new()
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);
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}
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}
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