辗转相除法求最大公约数，然后求出最小公倍数

 private static int minCommonMultiple(int m,int n){
        return n * m / maxCommonDivisor(m,n);
    }
    /**
      * 求最大公约数
      **/
    private static int maxCommonDivisor(int m,int n){
        if(m < n){// 确保m > n
            int t = m;
            m = n;
            n = t;
        }
        int t = 0;
        while ((t = m % n) != 0){
            m = n;
            n = t;
        }
        return n;
    }