lapieza.io - Assessment | Stock

input

8
1
4 9 5 2 6 7 8 1 8
1 3 0 0
0 0 1 1 3
2 6 0 0 1 7
2 6 1 0 1 7 1 1 3 4
0 1 2 3 4 5 6
0 1 2 0 1 6

output

0
7
2
3
7
6
6
6

stock.py

"""
lapieza.io - start up assessment
Github: @realFranco
July 21th, 2022

# PDF File "stock.pdf" contains the explanation in Espanish about my solution.

# Instructions
- Standard input output

# To pipe the results into a file
pytohn3 stock.py < input > output
cat output

# To watch the result on comand line
pytohn3 stock.py < input

tests = [
    [4, 9, 5, 2, 6, 7, 8, 1, 8],  # 7
    [1, 3, 0, 0],  # 2
    [0, 0, 1, 1, 3],  # 3
    [2, 6, 0, 0, 1, 7],  # 6
    [2, 6, 1, 0, 1, 7, 1, 1 , 3, 4],  # 7
    [0, 1, 2, 3, 4, 5, 6],  # 6  (Big O Worst case)
    [0, 1, 2, 0, 1, 6],  # 6
]
"""
import math
from typing import List


MAX = math.pow(10, 4) + 1
MIN = -MAX

class Solution:

    @staticmethod
    def collect_revenue(stock: List[int], revenue_chances: List) -> List[ List[int] ]:
        if len(stock) < 2:
            return []

        n_max, n_min = MIN, MAX
        i, n = 0, len(stock)
        while i < n:
            if stock[i] < n_min:
                n_min_iter = i
                n_min = stock[i]
                n_max = MIN  # Restart max
            
            if n_max < stock[i]:
                n_max_iter = i
                n_max = stock[i]
            
            # Making sure that buy happens before sell and prices are diffs.
            if n_max_iter > n_min_iter and n_min < n_max:
                revenue_chances.append([n_max, n_min])
                n_max, n_min = MIN, MAX
                i -= 1
            i += 1

        return revenue_chances


if __name__ == '__main__':
    n = int(input())
    for case in range(0, n):
        stock = list(map(int, input().split()))

        revenue_history = Solution.collect_revenue(stock=stock, revenue_chances=[])

        only_one_max = False
        max_price, lower_price = MIN, MAX
        profit = 0
        for commerce_action in revenue_history[::-1]:
            if commerce_action[1] < lower_price:
                lower_price = commerce_action[1]

            if only_one_max == False and max_price < commerce_action[0]:
                max_price = commerce_action[0]
                only_one_max = True

            # Collect local profit
            if profit < commerce_action[0] - commerce_action[1]:
                profit = commerce_action[0] - commerce_action[1]
   
        profit = max_price - lower_price if profit < max_price - lower_price else profit
        print(profit)

stock_solution_definition

> https://drive.google.com/file/d/1NZVqCK5DTfQmHAAn8_-CyDXg3OuJ91yM/view?usp=sharing