feature: best time to buy and sell stock ii lambda

solairerove · Nov 21, 2023 · 359648c · 359648c
1 parent 5b4ef5a
commit 359648c
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diff --git a/dynamic_programming/BestTimeToBuyAndSellStockII.py b/dynamic_programming/BestTimeToBuyAndSellStockII.py
@@ -1,3 +1,4 @@
+from functools import reduce
 from typing import List
 
 
@@ -9,3 +10,8 @@ def max_profit(self, prices: List[int]) -> int:
             res += prices[i] - prices[i - 1]
 
     return res
+
+
+# O(n) time || O(1) space
+def max_profit_lambda(self, prices: List[int]) -> int:
+    return reduce(lambda profit, i: profit + max(prices[i] - prices[i - 1], 0), range(1, len(prices)), 0)
diff --git a/dynamic_programming/test/test_max_profit_ii.py b/dynamic_programming/test/test_max_profit_ii.py
@@ -1,17 +1,20 @@
 import unittest
 
-from dynamic_programming.BestTimeToBuyAndSellStockII import max_profit
+from dynamic_programming.BestTimeToBuyAndSellStockII import max_profit, max_profit_lambda
 
 
 class MyTestCase(unittest.TestCase):
     def test_max_profit(self):
         self.assertEqual(7, max_profit(self, [7, 1, 5, 3, 6, 4]))
+        self.assertEqual(7, max_profit_lambda(self, [7, 1, 5, 3, 6, 4]))
 
     def test_max_profit_1(self):
         self.assertEqual(4, max_profit(self, [1, 2, 3, 4, 5]))
+        self.assertEqual(4, max_profit_lambda(self, [1, 2, 3, 4, 5]))
 
     def test_max_profit_2(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__':