DCP47 - Company's Stock Prices

'''
This problem was asked by Facebook.
Given a array of numbers representing the stock prices of a company in chronological order, write a function that calculates
the maximum profit you could have made from buying and selling that stock once. You must buy before you can sell it.
For example, given [9, 11, 8, 5, 7, 10], you should return 5, since you could buy the stock at 5 dollars and sell it at 10 dollars.
'''
from random import randrange

def solve(array):
    n = len(array)
    if n <= 1:
        return "The given array (" + str(array) + ") has length = " + str(n) + ", so I cannot find 2 numbers"
    maxProfit = array[0] - array[1]
    bigIndex = 0
    smallIndex = 1
    # So, I try to find 2 numbers big and small with these characteristics:
    # 1) big is right og small element in the given array
    # 2) The difference big - small be the maximum possible
    for i in range(0, n-1):
        for j in range(i, n):
            profit = array[j] - array[i]
            if profit > maxProfit:
                maxProfit = profit
                bigIndex = j
                smallIndex = i
    return maxProfit, array[bigIndex], array[smallIndex]


def prettyPrint(array):
    maxProfit, big, small = solve(array)
    print(str(array) + " ----> Max profit = " + str(big) + " - " + str(small) + " = " + str(maxProfit))

# MAIN FUNCTION
array1 = [9, 11, 8, 5, 7, 10]
array2 = [10, 7, 1, 6, 12, 4]
array3 = [randrange(20) + 1 for i in range(8)]
array4 = [randrange(100) + 1 for i in range(10)]
prettyPrint(array1)
prettyPrint(array2)
prettyPrint(array3)
prettyPrint(array4)