my $delim_reg   = ['A -3 C','C -4 B'];

                    \__i__/  \__j__/ --> sub-regions


my $array   =  
   ['A -4 A','A -1 C','C -4 D','D -4 B','B -3 C',  'C -2 B','B -1 E'];
                 
     |\_____i_______/                              \__j__/|-> Inst 1
     |____________________________________________________|


             |\_i__/  \_____j________/ |-------> Instance 2
             |_________________________|
                          
                         ... till
                          

    |\_____i_______/  \_______________j__________________/ |--> Inst 6
    |______________________________________________________|