Foundations Loops through pattern printing
26. Concentric Number Squares
Medium
Given an integer n, return the pattern below as a list of rows, top row first. Each row is a list of the
numbers in it, from left to right.
4 4 4 4 4 4 4
4 3 3 3 3 3 4
4 3 2 2 2 3 4
4 3 2 1 2 3 4
4 3 2 2 2 3 4
4 3 3 3 3 3 4
4 4 4 4 4 4 4
That is the pattern for n = 4. It is a square made of rings, one inside the other. The outer ring is all n,
the ring inside it is all n − 1, and so on, down to a single 1 in the centre. The square has
2n − 1 rows, and every row holds 2n − 1 numbers. For n = 4 the answer is
[[4,4,4,4,4,4,4],[4,3,3,3,3,3,4],[4,3,2,2,2,3,4],[4,3,2,1,2,3,4],[4,3,2,2,2,3,4],[4,3,3,3,3,3,4],[4,4,4,4,4,4,4]].
Example 1
Input: n = 4
Output:
4 4 4 4 4 4 4 4 3 3 3 3 3 4 4 3 2 2 2 3 4 4 3 2 1 2 3 4 4 3 2 2 2 3 4 4 3 3 3 3 3 4 4 4 4 4 4 4 4
Example 2
Input: n = 1
Output:
1Example 3
Input: n = 6
Output:
6 6 6 6 6 6 6 6 6 6 6 6 5 5 5 5 5 5 5 5 5 6 6 5 4 4 4 4 4 4 4 5 6 6 5 4 3 3 3 3 3 4 5 6 6 5 4 3 2 2 2 3 4 5 6 6 5 4 3 2 1 2 3 4 5 6 6 5 4 3 2 2 2 3 4 5 6 6 5 4 3 3 3 3 3 4 5 6 6 5 4 4 4 4 4 4 4 5 6 6 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6
Check your understanding
Work out the answer for this input before you write any code.
n = 2
Constraints
1 ≤ n ≤ 100
Clarifying questions
What you would ask an interviewer before writing any code.