Data commit

Task/Roman-numerals-Decode/Rust/roman-numerals-decode.rust

@@ -0,0 +1,35 @@
+struct RomanNumeral {
+    symbol: &'static str,
+    value: u32
+}
+
+const NUMERALS: [RomanNumeral; 13] = [
+    RomanNumeral {symbol: "M",  value: 1000},
+    RomanNumeral {symbol: "CM", value: 900},
+    RomanNumeral {symbol: "D",  value: 500},
+    RomanNumeral {symbol: "CD", value: 400},
+    RomanNumeral {symbol: "C",  value: 100},
+    RomanNumeral {symbol: "XC", value: 90},
+    RomanNumeral {symbol: "L",  value: 50},
+    RomanNumeral {symbol: "XL", value: 40},
+    RomanNumeral {symbol: "X",  value: 10},
+    RomanNumeral {symbol: "IX", value: 9},
+    RomanNumeral {symbol: "V",  value: 5},
+    RomanNumeral {symbol: "IV", value: 4},
+    RomanNumeral {symbol: "I",  value: 1}
+];
+
+fn to_hindu(roman: &str) -> u32 {
+    match NUMERALS.iter().find(|num| roman.starts_with(num.symbol)) {
+        Some(num) => num.value + to_hindu(&roman[num.symbol.len()..]),
+        None => 0, // if string empty, add nothing
+    }
+}
+
+fn main() {
+    let roms = ["MMXIV", "MCMXCIX", "XXV", "MDCLXVI", "MMMDCCCLXXXVIII"];
+    for &r in &roms {
+        // 15 is minimum formatting width of the first argument, there for alignment
+        println!("{:2$} = {}", r, to_hindu(r), 15);
+    }
+}