feature: best time to buy and sell stock lambda

solairerove · Nov 21, 2023 · 096b09b · 096b09b
1 parent 359648c
commit 096b09b
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Showing 2 changed files with 9 additions and 1 deletion.
diff --git a/dynamic_programming/BestTimeToBuyAndSellStock.py b/dynamic_programming/BestTimeToBuyAndSellStock.py
@@ -1,3 +1,4 @@
+from functools import reduce
 from typing import List
 
 
@@ -11,3 +12,8 @@ def max_profit(self, prices: List[int]) -> int:
             res = max(res, price - min_price)
 
     return res
+
+
+# O(n) time || O(1) space
+def max_profit_lambda(self, prices: List[int]) -> int:
+    return reduce(lambda acc, price: (min(acc[0], price), max(acc[1], price - acc[0])), prices[1:], (prices[0], 0))[1]
diff --git a/dynamic_programming/test/test_max_profit.py b/dynamic_programming/test/test_max_profit.py
@@ -1,14 +1,16 @@
 import unittest
 
-from dynamic_programming.BestTimeToBuyAndSellStock import max_profit
+from dynamic_programming.BestTimeToBuyAndSellStock import max_profit, max_profit_lambda
 
 
 class MyTestCase(unittest.TestCase):
     def test_max_profit(self):
         self.assertEqual(5, max_profit(self, [7, 1, 5, 3, 6, 4]))
+        self.assertEqual(5, max_profit_lambda(self, [7, 1, 5, 3, 6, 4]))
 
     def test_max_profit_1(self):
         self.assertEqual(0, max_profit(self, [7, 6, 4, 3, 1]))
+        self.assertEqual(0, max_profit_lambda(self, [7, 6, 4, 3, 1]))
 
 
 if __name__ == '__main__':