Create 01 - Recursive Approach (caused TLE).cpp

Author: JawadSher

24 - Dynamic Programming Problems/33 - Best Time To Buy and Sell Stock III/01 - Recursive Approach (caused TLE).cpp

@@ -0,0 +1,34 @@
+class Solution {
+public:
+    // Helper function to calculate maximum profit
+    int solve(vector<int>& prices, int index, int buy, int limit){
+        int n = prices.size();
+        
+        // Base case: if we've processed all days (index == n) or no more transactions can be made (limit == 0)
+        if(index == n || limit == 0) return 0;
+
+        int profit = 0;
+        
+        // If we are allowed to buy (buy == 1)
+        if(buy){
+            // Option 1: Buy the stock today and recurse for the next day with the buy flag set to 0 (indicating we can sell next)
+            // Option 2: Skip the current day and proceed to the next day with the buy flag still set to 1
+            profit = max((-prices[index] + solve(prices, index+1, 0, limit)), 
+                          (0 + solve(prices, index+1, 1, limit)));
+        } else {
+            // If we are allowed to sell (buy == 0)
+            // Option 1: Sell the stock today, reduce the transaction limit by 1 and proceed to the next day with buy flag set to 1
+            // Option 2: Skip the current day and proceed to the next day with buy flag still set to 0
+            profit = max((+prices[index] + solve(prices, index+1, 1, limit-1)), 
+                          (0 + solve(prices, index+1, 0, limit)));
+        }
+
+        return profit;
+    }
+
+    // Main function to return the maximum profit
+    int maxProfit(vector<int>& prices) {
+        // Starting from day 0, we can buy the stock, and we are allowed to make at most 2 transactions
+        return solve(prices, 0, 1, 2);
+    }
+};