42 lines
1.2 KiB
Python
42 lines
1.2 KiB
Python
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class Solution:
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def generateMatrix(self, n: int) -> List[List[int]]:
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if n==0: return []
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if n==1: return [[1]]
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matrix = [[0]*n for _ in range(n)]
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counter = 1
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rows, cols = n, n
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top, down = 0, rows-1
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left, right = 0, cols-1
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dir = 0
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while top<=down and left<=right:
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if dir==0:
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for i in range(left, right+1):
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matrix[top][i] = counter
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counter+=1
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top+=1
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elif dir==1:
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for i in range(top, down+1):
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matrix[i][right] = counter
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counter+=1
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right-=1
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elif dir==2:
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for i in range(right, left-1, -1):
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matrix[down][i] = counter
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counter += 1
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down-=1
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elif dir==3:
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for i in range(down, top-1, -1):
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matrix[i][left] = counter
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counter += 1
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left+=1
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dir = (dir+1)%4
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return matrix
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