29 lines
631 B
Rust
29 lines
631 B
Rust
use std::collections::HashMap;
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use std::ops::Index;
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use std::hash::Hash;
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#[derive(Debug)]
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pub struct Counter<T: Hash + Eq + Clone> {
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values: HashMap<T, usize>
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}
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impl <T: Hash + Eq + Clone> Counter<T> {
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pub fn new() -> Self {
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Self { values: HashMap::new() }
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}
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pub fn add(&mut self, collection: &[T]) {
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for x in collection {
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self.values.insert(x.clone(), self.values.get(&x).unwrap_or(&0) + 1);
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}
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}
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}
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impl <T: Hash + Eq + Clone> Index<T> for Counter<T> {
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type Output = usize;
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fn index(&self, idx: T) -> &usize {
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self.values.get(&idx).unwrap_or(&0)
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}
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}
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