leetcode_rust/
integer_to_roman.rs

1#![allow(dead_code)]
2
3pub fn int_to_roman(num: i32) -> String {
4    let mut res = String::from("");
5    let mut num = num;
6    while num >= 1000 {
7        res.push('M');
8        num -= 1000;
9    }
10    if num >= 900 {
11        res.push_str("CM");
12        num -= 900;
13    }
14    if num >= 500 {
15        res.push('D');
16        num -= 500;
17    }
18    if num >= 400 {
19        res.push_str("CD");
20        num -= 400;
21    }
22    while num >= 100 {
23        res.push('C');
24        num -= 100;
25    }
26    if num >= 90 {
27        res.push_str("XC");
28        num -= 90;
29    }
30    if num >= 50 {
31        res.push('L');
32        num -= 50;
33    }
34    if num >= 40 {
35        res.push_str("XL");
36        num -= 40;
37    }
38    while num >= 10 {
39        res.push('X');
40        num -= 10;
41    }
42    if num >= 9 {
43        res.push_str("IX");
44        num -= 90;
45    }
46    if num >= 5 {
47        res.push('V');
48        num -= 5;
49    }
50    if num >= 4 {
51        res.push_str("IV");
52        num -= 4;
53    }
54    while num >= 1 {
55        res.push('I');
56        num -= 1;
57    }
58
59    res
60}
61
62pub fn int_to_roman2(num: i32) -> String {
63    let romans = vec![
64        "M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I",
65    ];
66    let integers = vec![1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1];
67    let mut res = String::from("");
68    let mut num = num;
69    for (i, &val) in integers.iter().enumerate() {
70        while num >= val {
71            num -= val;
72            res.push_str(romans[i])
73        }
74    }
75
76    res
77}
78
79#[cfg(test)]
80mod tests {
81    use super::*;
82
83    #[test]
84    fn test1() {
85        assert_eq!(int_to_roman(1994), String::from("MCMXCIV"));
86    }
87
88    #[test]
89    fn test2() {
90        assert_eq!(int_to_roman2(1994), String::from("MCMXCIV"));
91    }
92}
leetcode_rust/integer_to_roman.rs

leetcode_rust/
integer_to_roman.rs
