text: Store sums ( a + b ) of all pairs ( a , b ) in a hash table
code: for ( int i = 0 ; i < n - 1 ; i ++ ) { for ( int j = i + 1 ; j < n ; j ++ ) { map . Add ( arr [ i ] + arr [ j ] , new Indexes ( i , j ) ) ; } } int d = int . MinValue ;