题解 | 矩阵乘法

row_A = int(input())

col_A = int(input())

row_B = col_A

col_B = int(input())

matrix_A = []
for i in range(row_A):
    row_of_A = input()
    row_of_A = list(map(int, row_of_A.split()))
    matrix_A.append(row_of_A)

matrix_B = []
for j in range(row_B):
    row_of_B = input()
    row_of_B = list(map(int, row_of_B.split()))
    matrix_B.append(row_of_B)

# Initialize the output matrix:
C = [[0 for _ in range(col_B)] for _ in range(row_A)]

for i in range(row_A):    
    for j in range(col_B):
        for k in range(col_A): # Important: Use a third index 'k' to separate indexing between C and (A&B).
            C[i][j] += matrix_A[i][k]*matrix_B[k][j]

for row in C:
    print(" ".join([str(num) for num in row]))