Problem Statement | |||||||||||||
| A 'quote' is a message from a stock exchange that says at what
price that exchange is currently willing to buy a given
stock (the 'bid') and what price it is willing to sell the stock (the
'ask'). The 'spread' is defined as the
difference between the ask and the bid. For our purposes,
you can assume that the ask will always be
greater than the bid and that the bid will be greater than zero.
The 'inside quote' is defined as the highest bid from any exchange and
the lowest ask from any exchange
(they do not necessarily need to be the same exchange). The inside
quote changes when any exchange
improves upon the current inside quote or when the best exchange moves
away from the inside exposing
a lower bid or higher ask. You will be given a String[] representing a number of quotes, in the order they are made. Each element of the input will represent a single quote and will be formatted as: "EXCHANGE BID ASK", where EXCHANGE is the index of the stock exchange making the quote and BID and ASK are as defined above. You are to issue a report based on the quotes. Each element of the report should be formatted as "EXCHANGE COUNT AVERAGE_SPREAD", where EXCHANGE is either the index of an EXCHANGE, as in the input, or 10, representing the inside quote. COUNT is the number of times that the quote (either bid or ask) for that exchange changed (or that the inside quote changed). AVERAGE_SPREAD is the average spread, averaged only over the quotes that caused the quote to change and with exactly 2 digits after the decimal point (rounded in the standard way to the nearest hundredth where .005 rounds up). The return should contain one entry for each exchange that issues one or more quotes in the input. It should be sorted by the index of the exchanges, with the entry for the inside spread coming last. | |||||||||||||
Definition | |||||||||||||
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Constraints | |||||||||||||
| - | Each element of quotes will be formatted as "EXCHANGE BID ASK" where EXCHANGE is a digit between '0' and '9', inclusive, and BID and ASK are integers between 1 and 1000, inclusive, without leading zeros. | ||||||||||||
| - | quotes will contain between 1 and 50 elements inclusive. | ||||||||||||
| - | An exchange will never issue a quote that is the same is its existing quote (so the number of times that its quote changes will be identical to the number of quotes it issues). | ||||||||||||
| - | ASK will be greater than BID in each element of quote. | ||||||||||||
| - | The inside spread will always be greater than 0. | ||||||||||||
Examples | |||||||||||||
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