LeetCode Best Time to Buy and Sell Stock II

屡明白就行了，就是找小的，然后找大的，没找到这样一个组合就进行一次交易，把利润加到结果里，继续找。假设小数是5大数是9，对于之间出现的按序的数比如6,7,8不影响结果，因此直接略过，但对于不安续出现的比如5，8,7，9这样的话因为可以进行两次交易，这样利润会更大。

int maxProfit(vector<int> &prices) {
	if(prices.size()==0||prices.size()==1)
		return 0;
	int sumprofit = 0;
	int buypoint=0,sellpoint=0;
	while(buypoint<prices.size())
	{
		while(buypoint<prices.size()-1&&prices[buypoint]>=prices[buypoint+1])
			buypoint++;
		sellpoint = buypoint + 1;
		if(sellpoint==prices.size())
			break;
		while(sellpoint<prices.size()-1&&prices[sellpoint]<=prices[sellpoint+1])
			sellpoint++;
		if(prices[sellpoint]>prices[buypoint])
			sumprofit += (prices[sellpoint]-prices[buypoint]);
		buypoint = sellpoint + 1;
	}
	return sumprofit;
}