52 lines
1.2 KiB
Plaintext
52 lines
1.2 KiB
Plaintext
use std::ops::Add;
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struct RangeFinder<'a, T: 'a> {
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index: usize,
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length: usize,
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arr: &'a [T],
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}
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impl<'a, T> Iterator for RangeFinder<'a, T> where T: PartialEq + Add<u8, Output=T> + Copy {
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type Item = (T, Option<T>);
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fn next(&mut self) -> Option<Self::Item> {
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if self.index == self.length {
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return None;
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}
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let lo = self.index;
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while self.index < self.length - 1 && self.arr[self.index + 1] == self.arr[self.index] + 1 {
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self.index += 1
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}
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let hi = self.index;
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self.index += 1;
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if hi - lo > 1 {
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Some((self.arr[lo], Some(self.arr[hi])))
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} else {
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if hi - lo == 1 {
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self.index -= 1
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}
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Some((self.arr[lo], None))
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}
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}
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}
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impl<'a, T> RangeFinder<'a, T> {
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fn new(a: &'a [T]) -> Self {
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RangeFinder {
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index: 0,
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arr: a,
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length: a.len(),
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}
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}
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}
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fn main() {
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let n = [0,1,2,3];
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for (i, (lo, hi)) in RangeFinder::new(&n).enumerate() {
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if i > 0 {print!(", ")}
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print!("{}", lo);
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if hi.is_some() {print!("-{}", hi.unwrap())}
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}
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println!("");
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}
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