best-time-to-buy-and-sell-stock py3

0121_best-time-to-buy-and-sell-stock/python3/solution.py

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+# Time: O(N)
+# Space: O(1)
+class Solution:
+    def maxProfit(self, prices: List[int]) -> int:
+        if len(prices) < 1: return 0
+        
+        i, j = 0, 1
+        max_profit = 0
+        
+        while i <= j < len(prices):
+            max_profit = max(prices[j] - prices[i], max_profit)
+            
+            # Buy low, sell high — so we need to keep moving i (like
+            # a buy pointer) if jth price is smaller than what ith is.
+            if prices[j] < prices[i]:
+                i = j
+            else:
+                j += 1
+        
+        return max_profit