combi sum 4 lc

class Solution {
    private int []nums;
    public int combinationSum4(int[] nums, int target) {
        this.nums = nums;
        Arrays.sort(this.nums);
        return bktr(target);
    }
    private int bktr(int remaining) {
        if (remaining == 0) {
            return 1;
        }
        int cnt = 0;
        for (int num : nums) {
            if (num > remaining) {
                break;
            }
            cnt += bktr(remaining - num);
        }
        return cnt;
    }
}