【算法题】求第N个丑数

public class Test6 {
    public static void main(String[] args) {
        System.out.println(getUglyNumber(10));
    }

    public static int getUglyNumber(int n) {
        if (n <= 0) {
            return 0;
        }
        int[] arr = new int[n];
        arr[0] = 1;
        int mul2 = 0;
        int mul3 = 0;
        int mul5 = 0;

        for (int i = 1; i < n; i++) {
            int min = Math.min(arr[mul2] * 2, Math.min(arr[mul3] * 3, arr[mul5] * 5));
            arr[i] = min;
            if (arr[mul2]*2==min){
                mul2++;
            }
            if (arr[mul3]*3==min){
                mul3++;
            }
            if (arr[mul5]*5==min){
                mul5++;
            }
        }
        return arr[n-1];
    }
}