Given an integer n, return a list of all simplified fractions between 0 and 1 (exclusive) such that the denominator is less-than-or-equal-to n. The fractions can be in any order. Example 1: Input: n = 2 Output: ["1/2"] Explanation: "1/2" is the only unique fraction with a denominator less-than-or-equal-to 2. Example 2: Input: n = 3 Output: ["1/2","1/3","2/3"] Example 3: Input: n = 4 Output: ["1/2","1/3","1/4","2/3","3/4"] Explanation: "2/4" is not a simplified fraction because it can be simplified to "1/2". Example 4: Input: n = 1 Output: [] Constraints: 1 <= n <= 100