求两个3´3 的矩阵的和。
测试1:
x = [[7, -5, 1],
[0, 2, 21],
[3, -11, 2]]
y = [[3, -6, 1],
[0, 12, 271],
[7, 1, 2]]
sum = [[0, 0, 0],
[0, 0, 0],
[0, 0, 0]] # 结果矩阵初始化
for i in range(0, 3): # 行
for j in range(0, 3): # 列
sum[i][j] = x[i][j] + y[i][j]
for z in sum: # 打印矩阵
print(z)



