text: /*
  
  You are given an array prices where prices[i] is the price of a given stock on the ith day.
  You want to maximize your profit by choosing a single day to buy one stock and choosing a different day in the future to sell that stock.
  Return the maximum profit you can achieve from this transaction. If you cannot achieve any profit, return 0.
  
  
  Example 1:
  Input: prices = [7,1,5,3,6,4]
  Output: 5
  Explanation: Buy on day 2 (price = 1) and sell on day 5 (price = 6), profit = 6-1 = 5.
  Note that buying on day 2 and selling on day 1 is not allowed because you must buy before you sell.
  
  Example 2:
  Input: prices = [7,6,4,3,1]
  Output: 0
  Explanation: In this case, no transactions are done and the max profit = 0.
  
  Constraints:
  
  1 <= prices.length <= 105
  0 <= prices[i] <= 104
  
  */
  
  class Solution {
  public:
      int maxProfit(vector<int>& prices) {
          int profit=0,cp=INT_MAX,diff;
          for(auto x:prices){
              if(x<=cp)
                  cp=x;
              else{
                  diff = x-cp;
                  profit=max(profit,diff);
              }
          }
          return profit;
      }
  };