Leetcode_Python 59 螺旋矩阵 II

class Solution(object):
    def generateMatrix(self, n):
        """
        :type n: int
        :rtype: List[List[int]]
        """
        matrix =  [[0]*n for _ in range(n)]
        rounds = (n+1)//2
        t = 1
        wide = high = n
        for i in range(rounds):  #轮次逐层计算  
            for j in range(4):  #表示4个边，我们顺时针计算
                if j == 0:  #表示上边
                    for z in range(i,wide - i):
                            matrix[i][z] = t
                            t += 1
                elif j == 1:  #表示右边
                    for z in range(i + 1,high - i):
                        matrix[z][wide- i -1] = t
                        t += 1
                elif j == 2 and high - i -1 != i: #下方
                    for z in range(wide - i - 2,i-1,-1):
                        matrix[high - i -1][z] = t
                        t += 1
                elif j == 3 and wide - i - 1 != i:
                    for z in range(high - i - 2,i,-1):
                        matrix[z][i] = t
                        t += 1
        return matrix