Function to find maximum equilibrium sum .
int findMaxSum ( int arr [ ] , int n ) { int sum = accumulate ( arr , arr + n , 0 ) ; int prefix_sum = 0 , res = INT_MIN ; for ( int i = 0 ; i < n ; i ++ ) { prefix_sum += arr [ i ] ; if ( prefix_sum == sum ) res = max ( res , prefix_sum ) ; sum -= arr [ i ] ; } return res ; }