Problem121.java

class Problem121 {

 public static void main(String[] args) {
 Problem121 p = new Problem121();
 int[] nums = {1,4,2};
 System.out.println(p.maxProfit(nums));
 }

 public int maxProfit1(int[] prices) {
 int max = Integer.MIN_VALUE;
 for (int i = prices.length-1; i > 0; i--) {
 for (int j = i-1; j >= 0; j--) {
 int profit = prices[i]-prices[j];
 max = profit > max ? profit: max;
 }
 }
 return max;
 }

 public int maxProfit(int[] prices) {
 int minprice = Integer.MAX_VALUE;
 int maxprofit = 0;
 for (int i = 0; i < prices.length; i++) {
 if (prices[i] < minprice)
 minprice = prices[i];
 else if (prices[i] - minprice > maxprofit)
 maxprofit = prices[i] - minprice;
 }
 return maxprofit;
 }
}