1447. Simplified Fractions.cpp

#
/*
Link: https://leetcode.com/problems/simplified-fractions/

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
*/

// Solution

/*
TC = O(n * n)
SC = O(1)
*/

class Solution {
public:
    int gcd(int a, int b) {
        if (b == 0)
            return a;
        return gcd(b, a % b);
    }
    vector<string> simplifiedFractions(int n) {
        vector<string> ans;
        string s;
        
        int i, j, temp;
        for (i = 1; i < n; i++) {
            for (j = i + 1; j <= n; j++) {
                if(gcd(i, j) == 1) {
                    string x = to_string(i);
                    string y = to_string(j);
                
                    s = x + "/" + y;
                    ans.push_back(s);
                }
                
            }
        }
        return ans;
    }
};