33 lines
687 B
Rust
33 lines
687 B
Rust
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use std::collections::HashMap;
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fn count_duplicates(text: &str) -> u32 {
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text.to_lowercase()
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.chars()
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.fold(HashMap::<char, u32>::new(), |mut hm, c| {
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hm.insert(c, hm.get(&c).copied().unwrap_or_default() + 1);
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hm
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})
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.values()
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.filter(|&&count| count > 1)
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.count() as u32
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn test_abcde() {
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assert_eq!(count_duplicates("abcde"), 0);
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}
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#[test]
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fn test_abcdea() {
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assert_eq!(count_duplicates("abcdea"), 1);
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}
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#[test]
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fn test_indivisibility() {
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assert_eq!(count_duplicates("indivisibility"), 1);
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}
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}
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