Programming challenge #1
by Charles Bovaird
Diagonal Sums on Spiral Matrices
Challenge - to write a program in any language to solve the following problem:
Starting with the number 1 and moving to the right in a clockwise direction a 5 by 5 spiral matrix is formed as follows:
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 both diagonals is 101. What is the sum of
both diagonals in a 1001 by 1001 spiral matrix formed the same way?
a) Create a program that will produce the diagonal sum for the 1001 by 1001 spiral matrix as well as other such matrices. Note: Some analysis would be initially useful.
b) What would be the program to determine all the diagonal sums for the spiral matrices from 1 to 1001?
Solutions should state clearly which language and version has been used and sent to: treasurer@dacs.org
Correct solutions will be recognized in future editions of DACS.DOC. |