Stores prefix and suffix sums
int [ ] prefix = new int [ N + 2 ] ; int [ ] suffix = new int [ N + 2 ] ; for ( int i = 0 ; i < N + 2 ; i ++ ) { prefix [ i ] = 0 ; } for ( int i = 0 ; i < N + 2 ; i ++ ) { suffix [ i ] = 0 ; }