Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. You may return the combinations in any order.

combination.java

// https://leetcode.com/problems/combination-sum/

class Solution {
    
    public List<List<Integer>> combinationSum(int[] candidates, int target) {
    
        Arrays.sort(candidates);
        List<List<Integer>> result = new ArrayList<List<Integer>>();
        getResult(result, new ArrayList<Integer>(), candidates, target, 0);
        
        return result;    
    }
    
    private void getResult(List<List<Integer>> result, List<Integer> cur, int candidates[], int target, int start) {
        
        
        // System.out.println(cur);
        if (target > 0) {
            for (int i = start; i < candidates.length && candidates[i] <= target; i++) {
                cur.add(candidates[i]);
                getResult(result, cur, candidates, target - candidates[i], i);
                cur.remove(cur.size() - 1);
            }    
        } else if(target == 0 ){
    		result.add(new ArrayList<Integer>(cur));
    	}
    }
}