(b) (5%) Use a stack to evaluate your postfix form (detail needed, show each step).

1. (10%) A lower triangular array A is an n-by-n array in which A[]0]== 0, if i <j. Assume that A is stored in one-dimensional array B sequentially, i.e, B[0] = A[0[0], B[1]=A[I][O], B[2] =AI] [1],B[B3]=A[2][0], B[4]=A[2][1], B[S]=A[2][2]J.... Write the addressing formula for the element A[/]U] stored in B[k] in the lower triangular part.