BestTime2BuySellStockII_122.java

/**
 * ----------------------------------------------------------------------------
   Best Time to Buy and Sell Stock II
    - 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 
      (ie, buy one and sell one share of the stock multiple times). 

    - However, you may not engage in multiple transactions at the same time 
      (ie, you must sell the stock before you buy again).
 * ----------------------------------------------------------------------------
 */

/**
 * - buy at every floor and sell at every ceiling
 * - This is equivalent to catch every pair of buy low, sell high.
 */

public class Solution {
    public int maxProfit(int[] prices) {
        int profit = 0;
        
        for(int i=1; i<prices.length; i++) 
            profit += Math.max(prices[i] - prices[i-1], 0);
        
        return profit;
    }
}