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Write better code: Day 1 - Apple Stock Prices

Arjun Rajkumar on December 05, 2018

This post originally appeared on Arjun Rajkumar's blog. Arjun is a web developer based in Bangalore, India. -- I'm going to spend 1-2 hours/day ...
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Arjun Rajkumar • • Edited

This was my logic for doing this.

Logic:

  • Go thru each price one by one.
  • See if the current stock is lesser than previous min_stock stored variable.
  • See if the profit is greater than max profit stored. (max_profit, pot_profit)
  • Going thru the loop once so it is O[n] time
  • O[1] space as storing fixed.

It works with these few example cases:
Examples: [10, 7, 5, 8, 11, 9] -> 6 ; [10, 7, 100, 8, 11, 9] -> 92 ; [10] -> 0 ; [10, 2] -> 0.

Code:
alt text

Github

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M Bellucci • • Edited

In ruby

possible_trades = stock_prices.combination(2).to_a
max_trade_index = possible_trades.map { |x,y| y-x }.each_with_index.max[1]
return possible_trades[max_trade_index]