···
class Solution {
public List<List<Integer>> permute(int[] nums) {
List<List<Integer>> lists = new ArrayList<>();
List<List<Integer>> result = new ArrayList<>();
if(nums.length == 1){
List<Integer> list = new ArrayList<>();
list.add(nums[0]);
lists.add(list);
return lists;
}
int []copy = new int[nums.length-1];
for(int i = 0 ; i < nums.length; i++){
for(int j = 0; j < nums.length; j++){
if(j < i){
copy[j] = nums[j];
} else if(j > i){
copy[j-1] = nums[j];
}
}
lists = permute(copy);
for(int j = 0; j < lists.size(); j++){
lists.get(j).add(nums[i]);
}
//return lists;
result.addAll(lists);
}
return result;
}
}
···
