Add 121_Best_Time_to_Buy_and_Sell_Stock.java

Author: Sean Prashad

Dynamic Programming/121_Best_Time_to_Buy_and_Sell_Stock.java

@@ -0,0 +1,19 @@
+class Solution {
+    public int maxProfit(int[] prices) {
+        if (prices == null || prices.length == 0) {
+            return 0;
+        }
+
+        int minPrices = prices[0], profit = 0;
+
+        for (int i = 1; i < prices.length; i++) {
+            if (prices[i] < minPrices) {
+                minPrices = Math.min(minPrices, prices[i]);
+            }
+
+            profit = Math.max(profit, prices[i] - minPrices);
+        }
+
+        return profit;
+    }
+}