LeetCode——全排列

import java.util.ArrayList;
import java.util.List;
import java.util.Stack;

public class FullSort {

    private  List<List<Integer>> lists = new ArrayList<List<Integer>>();
    public  List<List<Integer>> permute(int[] nums) {
        if(nums.length == 0) {
            return lists;
        }
        else{
            allSort(nums,new Stack<Integer>());
            return lists;
        }
    }
    //递归函数
    public  void allSort(int[]nums,Stack<Integer> stack)
    {
        //终止条件
        if(stack.size() == nums.length )
        {
            lists.add(new ArrayList<Integer>(stack));
            return;
        }
        for (int num : nums) {
            if( stack.contains(num) ) {
                continue;
            }
            stack.push(num);
            allSort(nums,stack);
　　　       //出栈
            stack.pop();
        }
    }
}