Problem: Find optimal parenthesization of a chain of matrices to be
multiplied such that the number of scalar multiplications is minimized.
Recall matrix multiplication algorithm:
for i = 1 to rows(A)
for j = 1 to cols(B)
C[i,j] = 0
for k = 1 to cols(A)
C[i,j] = C[i,j] + A[i,k] * B[k,j]
Thus the number of multiplications is p*q*r.