Added Python solution to 121_Best time to buy and sell stocks

Author: JoyKrishan

Algorithms/Easy/121_BestTimeToBuyAndSellStock/Solution.py

@@ -0,0 +1,15 @@
+class Solution:
+    def maxProfit(self, prices: List[int]) -> int:
+        left = 0
+        right = 1
+        max_profit = 0
+
+        while right < len(prices):
+            if prices[right] < prices[left]:
+                left = right
+                right += 1
+            else:
+                max_profit = max(max_profit, prices[right] - prices[left])
+                right += 1
+
+        return max_profit