Add best time to buy and sell stock solution

Author: hyunjung-choi

best-time-to-buy-and-sell-stock/hyunjung-choi.kt

@@ -0,0 +1,18 @@
+/**
+ * 시간 복잡도: O(n)
+ * 공간 복잡도: O(1)
+ */
+
+class Solution {
+    fun maxProfit(prices: IntArray): Int {
+        var minPrice = Int.MAX_VALUE
+        var maxProfit = 0
+
+        prices.forEach { price ->
+            minPrice = minOf(minPrice, price)
+            maxProfit = maxOf(maxProfit, price - minPrice)
+        }
+
+        return maxProfit
+    }
+}