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