2020-12-07 05:22:30 +00:00
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// Get two non-overlapping ranges starting at i & j, both with length len
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pub fn get_both_ranges<T>(
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2022-05-16 03:25:44 +00:00
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vector: &mut [T],
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2020-12-07 05:22:30 +00:00
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i: usize,
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j: usize,
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len: usize,
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) -> (&mut [T], &mut [T]) {
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debug_assert_ne!(i, j);
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debug_assert!(i + len <= vector.len());
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debug_assert!(j + len <= vector.len());
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if i < j {
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debug_assert!(i + len <= j);
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let (first, last) = vector.split_at_mut(j);
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return (&mut first[i..(i + len)], &mut last[0..len]);
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} else {
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debug_assert!(j + len <= i);
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let (first, last) = vector.split_at_mut(i);
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return (&mut last[0..len], &mut first[j..(j + len)]);
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}
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}
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2022-05-16 03:25:44 +00:00
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pub fn get_both_indices<T>(vector: &mut [T], i: usize, j: usize) -> (&mut T, &mut T) {
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2019-02-18 18:34:43 +00:00
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debug_assert_ne!(i, j);
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debug_assert!(i < vector.len());
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debug_assert!(j < vector.len());
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2019-02-13 06:11:19 +00:00
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if i < j {
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let (first, last) = vector.split_at_mut(j);
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2019-03-28 21:13:19 +00:00
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return (&mut first[i], &mut last[0]);
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} else {
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2019-02-13 06:11:19 +00:00
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let (first, last) = vector.split_at_mut(i);
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2019-03-28 21:13:19 +00:00
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return (&mut last[0], &mut first[j]);
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2019-02-13 06:11:19 +00:00
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}
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2019-03-28 21:13:19 +00:00
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}
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2023-02-03 02:07:41 +00:00
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// This should eventually become <https://doc.rust-lang.org/std/primitive.u64.html#method.div_ceil>
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// when it gets stabilized, and this function should be removed.
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// (1) the result is known to not overflow u32 from elsewhere;
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// (2) `denom` is known to not be `0` from elsewhere.
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// TODO this is definitely not always the case! Let's do something about it.
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pub fn int_div_ceil(num: u64, denom: u64) -> u32 {
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if num % denom == 0 {
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(num / denom) as u32
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} else {
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(num / denom + 1) as u32
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}
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}
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