This is a similar question to https://leetcode.com/discuss/interview-question/483660/google-phone-currency-conversion but with a twist.

Input:

• conversionRates - 2d float array of currency exchange rates.
  • [i][j] = conversion from 1 unit of i currency to j currency
    • [i][j] may be DIFFERENT than [j][i]
• startCurrency - integer
• endCurrency - integer

Output:

• Maximum endCurrency possible from startCurrency to endCurrency

Notes:

• Currency A -> B may be DIFFERENT than B->A conversion
• You cannot convert to the same currency more than once
• Up to 18 currencies