優達學城《計算機科學導論》 --判斷反對稱矩陣練習

# By Dimitris_GR from forums
# Modify Problem Set 31's (Optional) Symmetric Square to return True 
# if the given square is antisymmetric and False otherwise. 
# An nxn square is called antisymmetric if A[i][j]=-A[j][i] 
# for each i=0,1,...,n-1 and for each j=0,1,...,n-1.

def antisymmetric(A):
    for i in range(len(A)):
        for j in range(len(A)):
            if A[i][j]!=-1*A[j][i]:
                return 'FALSE'
                break
            elif i==len(A)-1 and j==len(A)-1:
                return 'TURE'
# Test Cases:
print antisymmetric([[0, 1, 2], 
                     [-1, 0, 3], 
                     [-2, -3, 0]])   
#>>> True


print antisymmetric([[0, 1, 2], 
                     [-1, 0, -2], 
                     [2, 2,  3]])
#>>> False