Best Time to Buy and Sell Stock II

Algorithm:

　　Scan through the array, keep finding

　　　　1.  prices[i] with the condition:  prices[i] < prices[i+1] or at the end of a descending trend, treat it as buying point

　　　　2.  prices[i] with the condition:  prices[i] > prices[i+1], or at the end of an ascending trend, treat it as selling point

　　keeping till reach the end of the array;

　　Note:

　　1. if a buying point is recorded and not reach the end, then must exist a selling point after it ( must exist some point larger than buying point)

　　2. if reach the end when finding the buying point, then stop and finish the whole programe. 

原文：http://www.cnblogs.com/jinagyuanhk/p/4194901.html