Leetcode#122 Best Time to Buy and Sell Stock II

 1 int maxProfit(vector<int> &prices) {
 2         if (prices.empty()) 
 3             return 0;
 4         
 5         int profit = 0;
 6         int climax = prices[prices.size() - 1];
 7         
 8         for (int i = prices.size() - 2; i >= 0; i--) {
 9             if (prices[i] >= prices[i + 1]) {
10                 profit += climax - prices[i + 1];
11                 climax = prices[i];
12             }
13         }
14         profit += climax - prices[0];
15         
16         return profit;
17 }