Data Structure Array: Maximum circular subarray sum

http://www.geeksforgeeks.org/maximum-contiguous-circular-sum/

 #include <iostream>
 #include <vector>
 #include <algorithm>
 #include <queue>
 #include <stack>
 #include <string>
 #include <fstream>
 #include <map>
 using namespace std;

 bool allneg(int arr[], int n) {
     for (int i = ; i < n; i++) {
         if (arr[i] > ) return false;
     }
     return true;
 }

 int maxsum(int arr[], int n) {
     int tmp = ;
     int ans = INT_MIN;
     for (int i = ; i < n; i++) {
         tmp += arr[i];
         ans = max(ans, tmp);
         tmp = max(tmp, );
     }
     return ans;
 }

 int maxcircular(int arr[], int n) {
     int ans = maxsum(arr, n);
     if (allneg(arr, n)) return ans;
     int sum = ;
     for (int i = ; i < n; i++) {
         sum += arr[i];
         arr[i] = -arr[i];
     }
     return max(ans, sum + maxsum(arr, n));
 }

 int main() {
     int arr[] = {, , -, , -, -, , -, };
     cout << maxcircular(arr, ) << endl;
     return ;
 }