122. Best Time to Buy and Sell Stock II

For this problem, we want to catch all the upside wave. So the problem becomes quite easy, i.e. as long as current price is larger than the last price we take the profit

1:  class Solution {  
2:  public:  
3:    int maxProfit(vector<int>& prices) {  
4:      int profit = 0;  
5:      for (int i = 1; i < prices.size(); i++) {  
6:        if (prices[i] > prices[i-1]) profit += prices[i]-prices[i-1];  
7:      }  
8:      return profit;  
9:    }  
10:  };