1. class Solution {
    2. public:
    3.     int maxProfit(vector<int>& prices) {
    5.         if(prices.size() <=0){
    6.             return 0;
    7.         }
    8.         int dp = 0;
    9.         int minP = 0;
    10.         minP = prices[0];
    11.         for (int i = 1; i < prices.size(); i++)
    12.         {
    13.             dp = max(dp , prices[i] - minP);
    14.             if(prices[i] < minP){
    15.                 minP = prices[i];
    16.             }
    18.         }
    19.         return dp;
    21.     }
    22. };