From 5c73343db850dbb6eb73143873e42a8558a6b523 Mon Sep 17 00:00:00 2001
From: chayan das <dasshuvo817@gmail.com>
Date: Mon, 29 Sep 2025 23:58:06 +0530
Subject: [PATCH] Create 29 September  Maximum subarray sum 2

---
 29 September  Maximum subarray sum 2 | 36 ++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 29 September  Maximum subarray sum 2

diff --git a/29 September  Maximum subarray sum 2 b/29 September  Maximum subarray sum 2
new file mode 100644
index 0000000..fd92b7f
--- /dev/null
+++ b/29 September  Maximum subarray sum 2	
@@ -0,0 +1,36 @@
+class Solution {
+  public:
+    int maxSubarrSum(vector<int>& arr, int a, int b) {
+        // code here
+        int n=arr.size();
+        
+        vector<long long> pref(n+1,0);
+        
+        for(int i=1;i<=n;i++){
+            pref[i]=pref[i-1]+arr[i-1];
+        }
+        
+        deque<int> dq;
+        
+        int maxSum=INT_MIN;
+        
+        for(int r=a;r<=n;r++){
+           int l=r-a;
+           
+           while (!dq.empty() && pref[dq.back()] >= pref[l]){
+               dq.pop_back();
+           }
+           
+           dq.push_back(l);
+           
+           while (!dq.empty() && dq.front() < r-b){
+                dq.pop_front();
+           }
+           
+           maxSum=max(maxSum,(int)(pref[r]-pref[dq.front()]));
+        }
+        
+        return maxSum;
+        
+    }
+};