Spiral Numbers in advance

Question

First, I would like to say thanks to Mr. Swapnil Srivastava for his post of coding challenges of Spiral Number. This is the best challenge for us to enhance our coding skills.
In this challenge, many coders solved the problem by using a 2D matrix to store numbers, then display the the matrix after computing and storing these numbers.
Think about when you face to solve the challenge with a big size of spiral matrix, say about 10,000, it will take about a minute to compute and fifteen minutes to display the matrix if you using this algorithm. Additional, we will spend a lot of resources, especially RAM to compute and to store the numbers.
So, my question is, how can we compute numbers and display it immediately? I mean, should we not use any iterators, but some variables, to resolve the problem?
Thank you.

Answer 1

Nezumi Neko there are no iterators in my code; only an array. I like your code. Haven't as yet figured out how it does it, but I will. You really shouldn't use tabs as your spacing falls apart. You can use this to fix it:
print("%3d" % (b - j + i), end=" ")

Answer 2

This code does it.
https://code.sololearn.com/cJ5UrgeiCONk

Answer 3

Updated to use your calculations:
https://code.sololearn.com/clR1qmhXhW9K

Answer 4

Immediately, isn't possible. You could calculate a number at a time to display starting with what would have been stored in matrix[0,0] to matrix[0,99]. Coming up with the formula would be tricky, but proving it out on 5x5 and 6x6 should prove it for all n's. It is definitely possible. I did it for each line by figuring out that 21-11 (4 down, 4 left, plus 3 up) gave 10. My guess is knowing what row you're working on keeping an array of the last number in each column you can calculate any size matrix like I just did for this.
25 24 23 22 21
10 9 8 7 20
11 2 1 6 19
12 3 4 5 18
13 14 15 16 17

Answer 5

John Wells , well, array in python is a kind of iterator. Thank you for your advice to fix its showing.

Answer 6

Vote for your algorithm, John Wells, but, yours still uses iterators. I found a way to solve this problem using some formulas. We could calculate then print the value of any item by using a couple nest for loops. I will post my code soon.

Answer 7

This is my code (written in python 3)

https://code.sololearn.com/cSxwk7c1AHr8/#py

Answer 8

Goodjob man, John Wells . Thanks for sharing 👍👍👍

Answer 9

Dammmmn, you <swear> are awesome!!!! I can only hope to become as good a coder as you guys. #CodersShapeTheWorld