leetcode-Spiral Matrix II 螺旋矩阵2之python大法好，四行就搞定，你敢信？

 Spiral Matrix II

 

螺旋矩阵

Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.

For example,
Given n = 3,

You should return the following matrix:

[
 [ 1, 2, 3 ],
 [ 8, 9, 4 ],
 [ 7, 6, 5 ]
]

　

　　看博客园有人面试碰到过这个问题，长篇大论看得我头晕。跑去leetcode讨论区，看来看去还是我python大法牛逼，四行就搞定了你敢信。。

| 1 | 2 | 3 |

| 8 | 9 | 4 |

| 7   6 | 5 |

如果看不明白的话，大致过程像上面这样，颜色相同表示在同一步骤里面执行

 

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>>> def generateMatrix(n): ...     A, low = [], n*n+1 ...     while low > 1: ...         low, high = low - len(A), low ...         A = [list(range(low, high))] + list(zip(*A[::-1]))  # python3.3 语法 与2.7会有差别 ...         print(A) ...     return A ... >>> generateMatrix(1) [[]] [[1]] [[1]] >>> generateMatrix(2) [[]] [[4]] [[3],  (4,)] [[1, 2],  (4, 3)] [[1, 2], (4, 3)] >>> generateMatrix(3) [[]] [[9]] [[8],  (9,)] [[6, 7],  (9, 8)] [[4, 5],  (9, 6),  (8, 7)] [[1, 2, 3],  (8, 9, 4),  (7, 6, 5)] [[1, 2, 3], (8, 9, 4), (7, 6, 5)]