package code;
import java.util.ArrayList;
import java.util.List;
/*
* 46. Permutations
* 题æ„：全排列
* 难度：Medium
* 分类：Backtracking
* æ€è·¯ï¼šå…¸åž‹çš„回溯题,注æ„判æ–下相åŒå…ƒç´ é‡å¤æ·»åŠ ,å’Œlc39,lc78åšæ¯”较
*/
public class lc46 {
public static void main(String[] args) {
int nums[] = {};
System.out.println(permute(nums).toString());
}
public static List> permute(int[] nums) {
List
> res = new ArrayList<>();
backtracking(res,nums,new ArrayList());
return res;
}
public static void backtracking(List
> res, int[] nums, List l){
if(l.size()==nums.length){
res.add(new ArrayList<>(l));
return;
}
for (int i = 0; i < nums.length ; i++) {
if(l.contains((Integer)nums[i])) //防æ¢ç›¸åŒçš„å…ƒç´ å†æ¬¡æ·»åŠ
continue;
l.add(nums[i]);
backtracking(res,nums,l);
l.remove((Integer)nums[i]);
}
}
}