22 lines
1.1 KiB
Markdown
22 lines
1.1 KiB
Markdown
I don't know why this problem has such a high number.
|
|
|
|
We simply parse all the roman numbers in the file and create minimal roman literals from them.
|
|
Then we simply sum all the length-differences together.
|
|
|
|
And it wasn't really hard to write algorithms for these two conversions. Both are pretty straight forward.
|
|
(And for number->roman we didn't even have to go the whole way, we only need the *length* of the result)
|
|
|
|
For the conversion roman->number we first search for the length of the roman literal.
|
|
Then we go backwards through the letters and get the value of each letter (cached by the array in line one).
|
|
If the value of the letter is greater than the last value we increment the total value (by the letter value),
|
|
otherwise we decrement it.
|
|
I found it easier to traverse the number backwards because we can cache the value of the last digit and do the algorithm this way with less `g` calls.
|
|
|
|
For the conversion number->optimal_roman_length i found this nice formula:
|
|
|
|
~~~
|
|
(n/1000) + R[(N%1000)/100] + R[(N%100)/10] + R[N%10]
|
|
|
|
// n is our number
|
|
// R is defined as an array with { 0, 1, 2, 3, 2, 1, 2, 3, 4, 2 }
|
|
~~~ |