Description
Given a positive integer n, generate an n x n matrix filled with elements from 1 to n2 in spiral order.
Example 1:
Input: n = 3 Output: [[1,2,3],[8,9,4],[7,6,5]]
Example 2:
Input: n = 1 Output: [[1]]
Constraints:
1 <= n <= 20
Solution
Python3
class Solution:
def generateMatrix(self, n):
res, lo = [[n*n]], n*n
while lo > 1:
lo, hi = lo - len(res), lo
#print('res:', res)
res = [[i for i in range(lo, hi)]] + [list(j) for j in zip(*res[::-1])]
return res