Given n, return n strings. Row i (1-based) counts down from i to 1, with the numbers
separated by single spaces.
Examples
Input: n = 3
Output: ["1", "2 1", "3 2 1"]
Input: n = 1
Output: ["1"]
Constraints
0 <= n <= 60- Return
[]whennis0.
Goals
- Use a decreasing range inside an outer loop
- Join numbers into a single space-separated string