Merge pull request #431 from apimpulse/main

MaxCircularSubarraySum.cpp

05. Arrays/MaxCircularSubarraySum.cpp

@@ -0,0 +1,72 @@
+//hacktoberfest2021
+
+#include<bits/stdc++.h>
+using namespace std;
+
+
+ // } Driver Code Ends
+
+class Solution{
+    public:
+    // arr: input array
+    // num: size of array
+    //Function to find maximum circular subarray sum.
+    int kadane(int arr[], int num){
+        int currentSum = arr[0];
+        int maxSum = arr[0];
+        for(int i=1; i<num; i++){
+            currentSum = max(arr[i], currentSum+arr[i]);
+            maxSum=max(maxSum, currentSum);
+        }
+        return maxSum;
+    }
+    int circularSubarraySum(int arr[], int num){
+
+        // your code here
+        int wrapsum;
+        int nonWrapsum;
+
+        nonWrapsum=kadane(arr, num);
+        int totalSum=0;
+        for(int i=0; i<num;i++){
+            totalSum+=arr[i];
+            arr[i]=-arr[i];
+        }
+        wrapsum=totalSum+kadane(arr, num);
+        //cout<<max(wrapsum, nonWrapsum);
+        if(wrapsum == 0)
+          wrapsum = INT_MIN;
+
+        return max(wrapsum, nonWrapsum);
+    }
+};
+
+// { Driver Code Starts.
+
+int main()
+ {
+	int T;
+
+	//testcases
+	cin>> T;
+
+	while (T--)
+	{
+	    int num;
+
+	    //size of array
+	    cin>>num;
+	    int arr[num];
+
+	    //inserting elements
+	    for(int i = 0; i<num; i++)
+	        cin>>arr[i];
+
+	    Solution ob;
+	    //calling function
+	    cout << ob.circularSubarraySum(arr, num) << endl;
+
+	}
+
+	return 0;
+}  // } Driver Code Ends