Create 01 - Recursive Approach (caused LTE).cpp

Author: JawadSher

24 - Dynamic Programming Problems/06 - Max Sum without Adjacents/01 - Recursive Approach (caused LTE).cpp

@@ -0,0 +1,65 @@
+// Apporach 1 : Left to Right Approach
+class Solution {
+  public:
+    // Recursive function to solve the problem
+    int solve(vector<int>& arr, int i, int n){
+        // Base case: If the index exceeds the size of the array, return 0 (no more elements to pick)
+        if(i > n) return 0;
+
+        // Base case: If we reach the last element, return its value
+        if(i == n) return arr[i];
+        
+        // Option 1: Include the current element arr[i] and move two steps forward (i+2)
+        int include = solve(arr, i+2, n) + arr[i];
+        
+        // Option 2: Exclude the current element arr[i] and move one step forward (i+1)
+        int exclude = solve(arr, i+1, n) + 0; // Adding 0 doesn't affect the result
+        
+        // Return the maximum sum between including and excluding the current element
+        return max(include, exclude);
+    }
+    
+    // Function to find the maximum sum without adjacent elements
+    int findMaxSum(vector<int>& arr) {
+        int n = arr.size();  // Get the size of the array
+        
+        // Start the recursive process from index 0
+        int sum = solve(arr, 0, n-1);
+        
+        return sum;  // Return the maximum sum obtained
+    }
+};
+
+// Approach 2 : Right to Left Approach
+class Solution {
+  public:
+    // Recursive function to solve the problem
+    int solve(vector<int>& arr, int n){
+        // Base case: If n is negative, we return 0 (no more elements to pick)
+        if(n < 0) return 0;
+
+        // Base case: If n is 0, return the first element
+        if(n == 0) return arr[0];
+        
+        // Option 1: Include the current element arr[n] and move two steps back (n-2)
+        int include = solve(arr, n-2) + arr[n];
+        
+        // Option 2: Exclude the current element arr[n] and move one step back (n-1)
+        int exclude = solve(arr, n-1) + 0; // Adding 0 doesn't affect the result
+        
+        // Return the maximum sum between including and excluding the current element
+        return max(include, exclude);
+    }
+    
+    // Function to find the maximum sum without adjacent elements
+    int findMaxSum(vector<int>& arr) {
+        int n = arr.size();  // Get the size of the array
+        
+        // Start the recursive process from the last index (n-1)
+        int sum = solve(arr, n-1);
+        
+        return sum;  // Return the maximum sum obtained
+    }
+};
+
+