Create Q-01: Best Time to Buy and Sell Stock I.java

Author: py3-coder

DP on Stocks/Q-01: Best Time to Buy and Sell Stock I.java

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+/*
+121. Best Time to Buy and Sell Stock
+
+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.
+
+Example 2:
+Input: prices = [7,6,4,3,1]
+Output: 0
+Explanation: In this case, no transactions are done and the max profit = 0.
+
+Constraints:
+1 <= prices.length <= 105
+0 <= prices[i] <= 104
+*/
+// TC : O(n) SC: O(1)
+
+import java.util.* ;
+
+public class Solution{
+    public static int maximumProfit(ArrayList<Integer> prices){
+        // Write your code here.
+        int mini=prices.get(0);
+        int profit=0;
+        for(int i=0;i<prices.size();i++){
+            int maxi = prices.get(i)-mini;
+            profit =Math.max(maxi,profit);
+            mini =Math.min(prices.get(i),mini);
+        }
+        return profit;
+    }
+}