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leetcode/source/integer_to_roman/mod.rs

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Rust
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2022-04-10 14:08:30 +00:00
pub fn int_to_roman(number: i32) -> String {
let mut result = String::new();
for (index, digit) in number.to_string().chars().rev().enumerate() {
if digit == '0' {
continue;
}
let digit = digit.to_digit(10).unwrap() as usize;
let magnitude = 10_usize.pow(index as u32);
let (unit_1, unit_5, unit_10) = match magnitude {
1 => ("I", "V", "X"),
10 => ("X", "L", "C"),
100 => ("C", "D", "M"),
1000 => ("M", "", ""),
_ => ("", "", ""),
};
result += &match digit {
1..=3 => unit_1.repeat(digit),
4 => format!("{unit_5}{unit_1}"),
5 => unit_5.to_string(),
6..=8 => format!("{}{unit_5}", unit_1.repeat(digit - 5)),
9 => format!("{unit_10}{unit_1}"),
_ => continue,
}
}
result.chars().rev().collect()
}