19、将一个一维数组转化为二进制表示矩阵。例如 [1,2,3] 转化为 [[0,0,1], [0,1,0], [0,1,1]]

num = 4
n19 = np.arange(num)
n191 = np.zeros(shape=(num,num),dtype='int')
for i in range(num):
    n = n19[i]
    for j in range(num-1,-1,-1):
        n191[i][j] = n%2
        n = n//2
n191