回溯算法形参的处理

public void backTracking(int[] candidates,int target,List<Integer> path,List<List<Integer>> res,int sum,int index){
        if(sum>target) return;
        if(sum==target){
            res.add(new ArrayList(path));
            return;
        }
       
        for(int i=index;i<candidates.length&&candidates[i]+sum<=target;i++){
             if(i>0&&candidates[i]==candidates[i-1]&&!used[i-1]){
            continue;
        }
            path.add(candidates[i]);
            used[i]=true;
            backTracking(candidates,target,path,res,sum+candidates[i],i+1);
            used[i]=false;
            path.remove(path.size()-1);
        }
    }

public void backTracking(int[] candidates,int target,List<Integer> path,List<List<Integer>> res,int sum,int index){
        if(sum>target) return;
        if(sum==target){
            res.add(new ArrayList(path));
            return;
        }
       
        for(int i=index;i<candidates.length&&candidates[i]+sum<=target;i++){
             if(i>0&&candidates[i]==candidates[i-1]&&!used[i-1]){
            continue;
        }
            path.add(candidates[i]);
            used[i]=true;
            sum+=candidates[i];
            backTracking(candidates,target,path,res,sum,i+1);
            sum-=candidates[i]
            used[i]=false;
            path.remove(path.size()-1);
        }
    }

sum值回溯可以通过传参的方法省去多余代码。