# 劍指offer

迴環矩陣

def rotation_matrix(n):
    arr = [[None for _ in range(n)] for _ in range(n)]
    right, down, left, up = n - 1, n - 1, 0, 0
    i, j = 0, 0  # i是行，j是列
    sum_ = 1
    while sum_ <= n * n:
        # right
        for j in range(left, right + 1):
            arr[i][j] = sum_
            sum_ +=
 
 1
        right -= 1
        # down
        for i in range(up+1, down+1):
            arr[i][j] = sum_
            sum_ += 1
        down -= 1
        # left
        for j in range(right, left-1, -1):
            arr[i][j] = sum_
            sum_ += 1
        left += 1
        # up
        for i in
 
 range(down, up, -1):
            arr[i][j] = sum_
            sum_ += 1
        up += 1
    return arr


if __name__ == '__main__':
    n = int(input('input:'))
    arr = rotation_matrix(n)
    for row in range(n):
        print(arr[row])

• 結果

/Library/Frameworks/Python.framework/Versions/3.6/bin
 
/python3.6 /Users/daidai/Desktop/刷題.py
input:5
[1, 2, 3, 4, 5]
[16, 17, 18, 19, 6]
[15, 24, 25, 20, 7]
[14, 23, 22, 21, 8]
[13, 12, 11, 10, 9]

Process finished with exit code 0