题解 | #没有重复项数字的所有排列#

public class Solution {
    public ArrayList<ArrayList<Integer>> permute(int[] num) {
        ArrayList<ArrayList<Integer>> result = new ArrayList<>();
        
        LinkedList<Integer> list = new LinkedList<>();
        
        backTrack(num,list,result);
        return result;
    }
    private void backTrack(int[] num, LinkedList<Integer> list, ArrayList<ArrayList<Integer>> result){
        if(list.size() == num.length){
            result.add(new ArrayList<Integer>(list));
            return;
        }
        for(int i = 0;i<num.length;i++){
            if(list.contains(num[i])){
                continue;
            }
            list.add(num[i]);
            backTrack(num,list,result);
            list.removeLast();
        }
    }
}