Best Time to Buy and Sell Stock II

题目

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).

方法 

和题目一的差别是：能够多次买入和卖出。

这样能够将题目：转换为求解所有上升的线段，仅仅要是上升的都增加到maxPro中去。 相邻的两个数求差，结果大于0。就增加到maxPro中去。

PS：也能够先求解连续的递增。在求差。

    public int maxProfit(int[] prices) {
    	if (prices == null) {
    		return 0;
    	}
    	int len = prices.length;
    	if (len == 0 || len == 1) {
    		return 0;
    	}
    	int maxProfit = 0;
    	for (int i = 1; i < len; i++) {
    		int temp = prices[i] - prices[i - 1];
    		if (temp > 0) {
    			maxProfit += temp;
    		}
    	}
    	return maxProfit;
    }