探讨了在形成螺旋矩阵时，如何通过观察规律计算出特定大小矩阵中两条对角线上的数字总和。该文以一个5x5的螺旋矩阵为例，介绍了计算方法，并提出挑战：求解1001x1001螺旋矩阵的对角线数字之和。
Starting with the number 1 and moving to the right in a clockwise direction a 5 by 5 spiral is formed as follows:
[b]21[/b] 22 23 24 [b]25[/b]
20 [b]7[/b] 8 [b]9[/b] 10
19 6 [b]1 [/b] 2 11
18 [b]5[/b] 4 [b]3[/b] 12
[b]17[/b] 16 15 14 [b]13[/b]
It can be verified that the sum of both diagonals is 101.
What is the sum of both diagonals in a 1001 by 1001 spiral formed in the same way?
直接总结下规律即可。
圈数为奇数，步长为2。每一圈有4个数，每个数构成等差数列，差为n-1。
[b]21[/b] 22 23 24 [b]25[/b]
20 [b]7[/b] 8 [b]9[/b] 10
19 6 [b]1 [/b] 2 11
18 [b]5[/b] 4 [b]3[/b] 12
[b]17[/b] 16 15 14 [b]13[/b]
It can be verified that the sum of both diagonals is 101.
What is the sum of both diagonals in a 1001 by 1001 spiral formed in the same way?
直接总结下规律即可。
圈数为奇数，步长为2。每一圈有4个数，每个数构成等差数列，差为n-1。
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