Problem 28

Problem 28

https://projecteuler.net/problem=28

Starting with the number 1 and moving to the right in a clockwise direction a 5 by 5 spiral is formed as follows:

从1开始，顺时针旋螺转，可得一个5*5的螺旋如下：

21 22 23 24 25
20  7  8  9 10
19  6  1  2 11
18  5  4  3 12
17 16 15 14 13

It can be verified that the sum of the numbers on the diagonals is 101.

对角线上的数字(粗体)之和等于101。

What is the sum of the numbers on the diagonals in a 1001 by 1001 spiral formed in the same way?

一个类似的1001*1001的螺旋的对角线上的数字之和为多少？

from math import pow

row = 1001
matrix = row * row
tot = [1]
spiral = [i for i in range(2, matrix+1)]
spiral = spiral[::-1]  # 倒序排列螺旋

interval = 1
count = 0
while True:
    try:
        for i in range(interval):  # 每隔interval个数字，加入一个数字至tot列表
            spiral.pop()
        tot.append(spiral.pop())
        count += 1
        if count == 4:  # 每加入四个数字，interval加二
            interval += 2
            count = 0
    except:
        break

print(sum(tot), tot)