leetcode/0059_spiral-matrix-ii/python3/amols_approach.py

42 lines
1.2 KiB
Python

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