Matrix Multiplication

Problem: Multiply the given 2 matrixes.

Solution in Python:

def multiply(A, B):
    """
    Author: Mayur P Srivastava
    """


    m1, n1 = shape(A)
    m2, n2 = shape(B)

    if not can_multiply(m1, n1, m2, n2):
        return None

    C = create_matrix(m1, n2)

    for i in range(m1):
        for j in range(n2):
            c = 0
            for k in range(n1):
                c += A[i][k] * B[k][j]
            C[i][j] = c

    return C

def shape(A):
    m = len(A)   
    n = 0
    for row in A:
        n2 = len(row)
        if n == 0:
            n = n2
        elif n != n2:
            assert False

    return m, n

def can_multiply(m1, n1, m2, n2):
    return n1 == m2

def create_matrix(m, n, value=0):
    matrix = []
    for i in range(m):
        row = []
        for j in range(n):
            row.append(value)
        matrix.append(row)
    return matrix

Concepts Learned: Maths