Я пытаюсь реализовать алгоритм с помощью питона Straßen и я получаю ошибку

Question

вот мой код:

# n*n additions 

def add(A, B): 
    n = len(A) 
    C = [[0 for j in range(n)] for i in range(n)] 
    for j in range(n): 
     for i in range (n): 
      C[i][j] = A[i][j] + B[i][j] 
    return C 


# n*n subtraction 

def sub(A, B): 
    n = len(A) 
    C = [[0 for j in range(n)] for i in range(n)] 
    for i in range(n): 
     for j in range(n): 
      C[i][j] = A[i][j] - B[i][j] 
    return C 

def strassens(A, B): 
    # Implementation of the strassen algorithm 

    n = len(A[0]) 
    C = [[0 for j in range(n)] for i in range(n)] 
    if n==1: 
     C[0][0] = A[0][0]*B[0][0] 
    else: 


     # the new sub-matrices by dividing n (n/2) 
     m = n/2 
     A11 = [[0 for j in range(m)] for i in range(m)] 
     A12 = [[0 for j in range(m)] for i in range(m)] 
     A21 = [[0 for j in range(m)] for i in range(m)] 
     A22 = [[0 for j in range(m)] for i in range(m)] 

     B11 = [[0 for j in range(m)] for i in range(m)] 
     B12 = [[0 for j in range(m)] for i in range(m)] 
     B21 = [[0 for j in range(m)] for i in range(m)] 
     B22 = [[0 for j in range(m)] for i in range(m)] 

     AR = [[0 for j in range(m)] for i in range(m)] 
     BR = [[0 for j in range(m)] for i in range(m)] 

     # create 4 sub-matrices(top left, top right bottom letf and right: 
     for i in range(m): 
      for j in range(m): 
       A11[i][j] = A[i][j]    
       A12[i][j] = A[i][j + m] 
       A21[i][j] = A[i + m][j]  
       A22[i][j] = A[i + m][j + m] 

       B11[i][j] = B[i][j]    
       B12[i][j] = B[i][j + m]  
       B21[i][j] = B[i + m][j]  
       B22[i][j] = B[i + m][j + m] 

     # making the calculation for all the ps 


      BR = sub(B12, B22) #(b12-b22) 
      p1 = strassens(A11, BR) # p1 = (a11) * (b12-b22) 

      AR = add(A11, A12)  # a11 + a12 
      p2 = strassens(AR, B11) # p2 = (a21+a22) * (b11) 

      AR = add(A21, A22) # a21 + a22 
      p3 = strassens(B11, AR) # p3 = (b11) * (a21 + a22) 

      BR = sub(B21, B11) # b21 - b11 
      p4 =strassens(A22, BR) # p4 = (a22) * (b21 - b11) 

      BR = add(B11,B22)  #b11+b22 
      AR = add(A11, A12)  # a11 + a12 
      p5 = strassens(AR, BR) # p5 = (a11+a12) * (b11+b22) 

      AR = sub(A12, A22) # a12 - a22 
      BR = add(B21, B22)  # b11 + b12 
      p6 = strassens(AR, BR) # p6 = (a21-a11) * (b11+b12) 

      AR = sub(A11, A21) # a12 - a21 
      BR = add(B11, B12)  # b11 + b12 
      p7 = strassens(AR, BR) # p7 = (a12-a21) * (b11+b12) 

     # reqrouping all the ps into c11, c22,c21,c12 

      AR = add(p5, p4) # p5 + p4 
      BR = add(AR, p6) # p5 + p4 + p6 
      c11 = sub(BR, p2) # c11 = p1 + p4 - p2 + p6 

      c12 = add(p1, p2) # c12 = p1 + p2 
      c21 = add(p3, p4) # c21 = p3 + p4 



      AR = add(p5, p1) # p5 + p1 
      BR = sub(AR, p3) # p5 + p1 - p3 
      c22 = sub(BR, p7) # c22 = p5 + p1 - p3 - p7 

     # Grouping the results obtained in a single matrix: 
      C = [[0 for j in range(n)] for i in range(n)] 
      for i in range(m): 
       for j in range(m): 
        C[i][j] = c11[i][j] 
        C[i][j + m] = c12[i][j] 
        C[i + m][j] = c21[i][j] 
        C[i + m][j + m] = c22[i][j] 
      return C 

здесь ошибка, что я получаю:

>>> a=[[1,2,4],[0,2,3]] 
>>> b=[[9,2,4],[0,2,3]] 

>>> strassens(a,b) 
Traceback (most recent call last): 
    File "<pyshell#3>", line 1, in <module> 
    strassens(a,b) 
    File "C:\Python33\Python\homework.py", line 34, in strassens 
    A11 = [[0 for j in range(m)] for i in range(m)] 
TypeError: 'float' object cannot be interpreted as an integer 

Answer 1

В Python 3 , вам нужно использовать // для int division. / дает поплавок:

m = n // 2