题解 | #没有重复项数字的所有排列#

import java.util.*;

public class Solution {
    static ArrayList<ArrayList<Integer>> res = new ArrayList<>();
    static ArrayList<Integer> list = new ArrayList<>();
    public static void F(int[] num,int n){
        if(list.size() >= n){
            ArrayList<Integer> newList = new ArrayList<>();
            for(Integer i : list){
                newList.add(i);
            }
            res.add(newList);
            return;
        }
        for(int i=0;i<n;i++){
            if(!list.contains(num[i])){
                list.add(num[i]);
                F(num,n);
                list.remove(list.size()-1);
            }
        }
    }
    public ArrayList<ArrayList<Integer>> permute(int[] num) {
        F(num,num.length);
        return res;
    }
}