feat: if/else 문 사용

Author: gyeo-ri

best-time-to-buy-and-sell-stock/gyeo-ri.py

@@ -0,0 +1,30 @@
+class Solution:
+    def maxProfit(self, prices: list[int]) -> int:
+        max_profit = 0
+        buy_at = None
+
+        for p in prices:
+            if buy_at is None:
+                buy_at = p
+            elif buy_at > p:
+                buy_at = p
+            elif buy_at < p:
+                max_profit = max(max_profit, p - buy_at)
+
+        return max_profit
+
+
+if __name__ == "__main__":
+    test_cases = [
+        ([7, 1, 5, 3, 6, 4], 5),
+        ([7, 6, 4, 3, 1], 0),
+        ([2, 4, 1], 2),
+    ]
+
+    solution = Solution()
+    for idx, case_ in enumerate(test_cases):
+        prices, answer = case_
+        result = solution.maxProfit(prices)
+        assert (
+            answer == result
+        ), f"Test Case {idx} Failed: Expected {answer}, Got {result}"