RosettaCodeData/Task/Roman-numerals-Encode/D/roman-numerals-encode.d

27 lines
669 B
D

string toRoman(int n) pure nothrow
in {
assert(n < 5000);
} body {
static immutable weights = [1000, 900, 500, 400, 100, 90,
50, 40, 10, 9, 5, 4, 1];
static immutable symbols = ["M","CM","D","CD","C","XC","L",
"XL","X","IX","V","IV","I"];
string roman;
foreach (i, w; weights) {
while (n >= w) {
roman ~= symbols[i];
n -= w;
}
if (n == 0)
break;
}
return roman;
} unittest {
assert(toRoman(455) == "CDLV");
assert(toRoman(3456) == "MMMCDLVI");
assert(toRoman(2488) == "MMCDLXXXVIII");
}
void main() {}