CHAIN 1: d = [10, 20, 3, 5, 30]  (A1 10x20, A2 20x3, A3 3x5, A4 5x30)

  l=2  M[1,2]  k=1:  M[1,1]=0 + M[2,2]=0 + 10*20*3=600  ->  600
  => M[1,2] = 600, c[1,2] = 1

  l=2  M[2,3]  k=2:  M[2,2]=0 + M[3,3]=0 + 20*3*5=300  ->  300
  => M[2,3] = 300, c[2,3] = 2

  l=2  M[3,4]  k=3:  M[3,3]=0 + M[4,4]=0 + 3*5*30=450  ->  450
  => M[3,4] = 450, c[3,4] = 3

  l=3  M[1,3]  k=1:  M[1,1]=0 + M[2,3]=300 + 10*20*5=1000  ->  1300
  l=3  M[1,3]  k=2:  M[1,2]=600 + M[3,3]=0 + 10*3*5=150  ->  750
  => M[1,3] = 750, c[1,3] = 2

  l=3  M[2,4]  k=2:  M[2,2]=0 + M[3,4]=450 + 20*3*30=1800  ->  2250
  l=3  M[2,4]  k=3:  M[2,3]=300 + M[4,4]=0 + 20*5*30=3000  ->  3300
  => M[2,4] = 2250, c[2,4] = 2

  l=4  M[1,4]  k=1:  M[1,1]=0 + M[2,4]=2250 + 10*20*30=6000  ->  8250
  l=4  M[1,4]  k=2:  M[1,2]=600 + M[3,4]=450 + 10*3*30=900  ->  1950
  l=4  M[1,4]  k=3:  M[1,3]=750 + M[4,4]=0 + 10*5*30=1500  ->  2250
  => M[1,4] = 1950, c[1,4] = 2

  M table (blank below the diagonal):
           j=1     j=2     j=3     j=4
  i=1        0     600     750    1950
  i=2        .       0     300    2250
  i=3        .       .       0     450
  i=4        .       .       .       0

  c table (only j > i is meaningful):
           j=1     j=2     j=3     j=4
  i=1        -       1       2       2
  i=2        -       -       2       2
  i=3        -       -       -       3
  i=4        -       -       -       -

  optimal cost      = 1950
  optimal grouping  = ((A1A2)(A3A4))


CHAIN 2: d = [30, 1, 40, 10, 25]  (A 30x1, B 1x40, C 40x10, D 10x25)
  M table (blank below the diagonal):
           j=1     j=2     j=3     j=4
  i=1        0    1200     700    1400
  i=2        .       0     400     650
  i=3        .       .       0   10000
  i=4        .       .       .       0

  c table (only j > i is meaningful):
           j=1     j=2     j=3     j=4
  i=1        -       1       1       1
  i=2        -       -       2       3
  i=3        -       -       -       3
  i=4        -       -       -       -

  optimal cost      = 1400
  optimal grouping  = (A1((A2A3)A4))
