49 lines
1.5 KiB
Rust
49 lines
1.5 KiB
Rust
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/*!
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# Description
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Given a string containing only the characters `x` and `y`, find whether there are the same number of `x`s and `y`s.
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balanced("xxxyyy") => true
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balanced("yyyxxx") => true
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balanced("xxxyyyy") => false
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balanced("yyxyxxyxxyyyyxxxyxyx") => true
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balanced("xyxxxxyyyxyxxyxxyy") => false
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balanced("") => true
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balanced("x") => false
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## Optional bonus
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Given a string containing only lowercase letters, find whether every letter that appears in the string appears the same number of times. Don't forget to handle the empty string (`""`) correctly!
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balanced_bonus("xxxyyyzzz") => true
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balanced_bonus("abccbaabccba") => true
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balanced_bonus("xxxyyyzzzz") => false
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balanced_bonus("abcdefghijklmnopqrstuvwxyz") => true
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balanced_bonus("pqq") => false
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balanced_bonus("fdedfdeffeddefeeeefddf") => false
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balanced_bonus("www") => true
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balanced_bonus("x") => true
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balanced_bonus("") => true
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Note that `balanced_bonus` behaves differently than `balanced` for a few inputs, e.g. `"x"`.
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*/
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use std::collections::HashMap;
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fn main() {
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println!("{}", balanced(String::from("jbsssssh")));
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}
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fn balanced(input: String) -> bool {
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let count: HashMap<char, i32> = input.chars().fold(HashMap::new(), |mut map, ch| {
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map.entry(ch).and_modify(|n| *n += 1).or_insert(1);
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map
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});
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println!("{:?}", count);
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let mut values = count.values();
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if let Some(first) = values.next() {
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values.all(|x| x == first)
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} else {
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true
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}
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}
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