lintcode-medium-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).

 Given an example [2,1,2,0,1], return 2.

 

这题就简单一点，因为可以随意做任意交易，所以只要后一天比前一天价格高，就可以在profit中加上这个差值

class Solution {
    /**
     * @param prices: Given an integer array
     * @return: Maximum profit
     */
    public int maxProfit(int[] prices) {
        // write your code here
        
        if(prices == null || prices.length == 0)
            return 0;
        
        int profit = 0;
        
        for(int i = 1; i < prices.length; i++){
            if(prices[i] > prices[i - 1])
                profit += prices[i] - prices[i - 1];
        }
        return profit;
    }
};