best-time-to-buy-and-sell-stock-II.py

# -*- coding: utf-8 -*-
"""
Created on Sun Apr  5 22:46:38 2020

@author: johnoyegbite
"""
# SOLVED!
"""
Problem:
    Say you have an array for which the ith element is the price of a given
    stock on day i.

    Design an algorithm to find the maximum profit.
    You may complete as many transactions as you like (i.e., buy one and sell
    one share of the stock multiple times).

    Note: You may not engage in multiple transactions at the same time
    (i.e., you must sell the stock before you buy again).

Example 1:
    Input: [7,1,5,3,6,4]
    Output: 7
    Explanation: Buy on day 2 (price = 1) and sell on day 3 (price = 5),
                 profit = 5-1 = 4.
                 Then buy on day 4 (price = 3) and sell on day 5 (price = 6),
                 profit = 6-3 = 3.

Example 2:
    Input: [1,2,3,4,5]
    Output: 4
    Explanation: Buy on day 1 (price = 1) and sell on day 5 (price = 5),
                 profit = 5-1 = 4.
                 Note that you cannot buy on day 1, buy on day 2 and sell them
                 later, as you are engaging multiple transactions at the same
                 time. You must sell before buying again.
Example 3:
    Input: [7,6,4,3,1]
    Output: 0
    Explanation: In this case, no transaction is done, i.e. max profit = 0.
"""


def maxProfit(prices):
    """
    :type prices: List[int]
    :rtype: int
    """
    max_profit = 0
    for i, num in enumerate(prices):
        if i > 0:
            buy = prices[i-1]
            sell = prices[i]
            if sell > buy:
                max_profit += sell - buy

    return max_profit


if __name__ == "__main__":
    prices = [7, 1, 5, 3, 6, 4]
    print(maxProfit(prices))