1447. 最简分数

题目链接：https://leetcode-cn.com/problems/simplified-fractions/

class Solution {
    public List<String> simplifiedFractions(int n) {
        List<String> list = new LinkedList<>();
        if (n == 1) {
            return list;
        }
        for (int i = 1; i < n; i++) {
            for (int j = i+1; j <= n; j++) {
                if (gcd(i,j) == 1) {
                    list.add(i+"/"+j);
                }
            }
        }
        return list;
    }
    public int gcd(int a, int b) {
        int c = a % b;
        while (c != 0) {
            a = b;
            b = c;
            c = a % b;
        }
        return b;
    }
}