Max profit on Buy and Sell stock

src/main/kotlin/Main.kt

@@ -1,5 +1,7 @@
 package main.kotlin
 
+import main.kotlin.dsalgoleetcode.BuyAndSellStock
+import main.kotlin.dsalgoleetcode.ContainsDuplicate
 import main.kotlin.dsalgoleetcode.LinkedListCycleDetection
 import main.kotlin.dsalgoleetcode.ListNode
 import main.kotlin.dsalgoleetcode.LongestSubstring
@@ -32,9 +34,14 @@ fun main() {
     println("Has cycle $llcdResult")
 
     // Calling Contains Duplicate
-    val `containsDuplicate.kt` = `ContainsDuplicate.kt`()
-    val containsDuplicateResult = `containsDuplicate.kt`
+    val containsDuplicate = ContainsDuplicate()
+    val containsDuplicateResult = containsDuplicate
         .containsDuplicate(intArrayOf(1,2,3,1,0,1))
     println("Contains Duplicate Integers $containsDuplicateResult")
 
+    // Calling Buy and Sell Stock
+    val buyAndSellStock = BuyAndSellStock()
+    val bnsResult = buyAndSellStock.maxProfit(intArrayOf(1,4,8,0,2))
+    println("Max profit : $bnsResult")
+
 }

src/main/kotlin/dsalgoleetcode/BuyAndSellStock.kt

@@ -0,0 +1,33 @@
+package main.kotlin.dsalgoleetcode
+
+/**
+ * You are given an array prices where prices[i] is the price of a given stock on the ith day.
+ * You want to maximize your profit by choosing a single day to buy one stock and choosing a
+ * different day in the future to sell that stock.
+ * Return the maximum profit you can achieve from this transaction.
+ * If you cannot achieve any profit, return 0.
+Example 1:
+
+Input: prices = [7,1,5,3,6,4]
+Output: 5
+Explanation: Buy on day 2 (price = 1) and sell on day 5 (price = 6), profit = 6-1 = 5.
+Note that buying on day 2 and selling on day 1 is not allowed because you must buy before you sell.
+ * */
+
+class BuyAndSellStock {
+
+    fun maxProfit(prices: IntArray): Int {
+
+        var minPrice = Int.MAX_VALUE
+        var maxProfit = 0
+
+        for (price in prices){
+            if( price < minPrice){
+                minPrice = price
+            } else{
+                maxProfit = maxOf(maxProfit, price - minPrice)
+            }
+        }
+        return maxProfit
+    }
+}

src/main/kotlin/dsalgoleetcode/ContainsDuplicate.kt.kt

@@ -12,7 +12,7 @@ package main.kotlin.dsalgoleetcode
  * The element 1 occurs at the indices 0 and 3.
  * */
 
-class `ContainsDuplicate.kt` {
+class ContainsDuplicate {
 
     fun containsDuplicate(nums: IntArray): Boolean {