Maximum Stock Profit in a single transaction

/*List of stock prices are given, find out maximum profit to get by buy and sell in a single transaction

prices = { 23, 28, 5, 6, 18, 15 }
*/


Solution:

public int maxProfit(int[] prices) {  
   int minPrice = Integer.MAX_VALUE;
   int maxProfit = 0;
   for(int price : prices) {
       maxProfit = Math.max(maxProfit, price-minPrice);
       minPrice = Math.min(minPrice, price);
   }
   return maxProfit;
 }  

This can be done in time O(n) with O(1) spaces