Daily Programmer exercises
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/*!
# Description
Given a string containing only the characters `x` and `y`, find whether there are the same number of `x`s and `y`s.
balanced("xxxyyy") => true
balanced("yyyxxx") => true
balanced("xxxyyyy") => false
balanced("yyxyxxyxxyyyyxxxyxyx") => true
balanced("xyxxxxyyyxyxxyxxyy") => false
balanced("") => true
balanced("x") => false
## Optional bonus
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!
balanced_bonus("xxxyyyzzz") => true
balanced_bonus("abccbaabccba") => true
balanced_bonus("xxxyyyzzzz") => false
balanced_bonus("abcdefghijklmnopqrstuvwxyz") => true
balanced_bonus("pqq") => false
balanced_bonus("fdedfdeffeddefeeeefddf") => false
balanced_bonus("www") => true
balanced_bonus("x") => true
balanced_bonus("") => true
Note that `balanced_bonus` behaves differently than `balanced` for a few inputs, e.g. `"x"`.
*/
use std::collections::HashMap;
fn main() {
println!("{}", balanced(String::from("jbsssssh")));
}
fn balanced(input: String) -> bool {
let count: HashMap<char, i32> = input.chars().fold(HashMap::new(), |mut map, ch| {
map.entry(ch).and_modify(|n| *n += 1).or_insert(1);
map
});
println!("{:?}", count);
let mut values = count.values();
if let Some(first) = values.next() {
values.all(|x| x == first)
} else {
true
}
}