roblox OA lifting weights 自己根据subsets改的

class Solution {
    public List<List<Integer>> combinationSum2(int[] nums, int target) {
        //cc
        int result = 0;
        int difference = Math.MAX_VALUE;

        if (nums == null || nums.length == 0)
            return result;
        
        //排序一下
        Arrays.sort(nums);
        
        backtrace(nums, new ArrayList<Integer>(), 0, 0,
                         target, difference, result);
        
        return result;
    }
    
    public void backtrace(int[] nums, List<Integer> temp, int start, 
                          int currentSum,
                          int target, int difference, int result) {
        //exit
        if (currentSum > target) {
            return ;
        }else {
            if (target - currentSum < difference) {
                difference = target - currentSum;
                result = currentSum;
            }

            for (int i = start; i < nums.length; i++) {
                if (i > start && nums[i] == nums[i - 1]) //重复的压根不能用
                    continue;
            
                temp.add(nums[i]);
                backtrace(nums, temp, i, currentSum + nums[i],
                         target, difference, result);
                temp.remove(temp.size() - 1);
            }
        }
    }
}