15. Permutations/46. Permutations

• 本题难度: Medium
• Topic: Search & Recursion

Description

Given a list of numbers, return all possible permutations.

Example

Example 1:

Input: [1]

Output:

[

[1]]

Example 2:

Input: [1,2,3]

Output:

[

[1,2,3],

[1,3,2],

[2,1,3],

[2,3,1],

[3,1,2],

[3,2,1]]

Challenge

Do it without recursion.

Notice

You can assume that there is no duplicate numbers in the list.

我的代码

class Solution:
    """
    @param: nums: A list of integers.
    @return: A list of permutations.
    """
    def permute(self, nums):
        # write your code here

        # recursion
        res = []
        self.dfs(nums,[],res,len(nums))
        return res

    def dfs(self,nums,path,res,n):
        if len(path)==n:
            res.append(path)
        for i in range(len(nums)):
            self.dfs(nums[:i]+nums[i+1:],path+[nums[i]],res,n)
           

思路

简单版的16. Permutations II/47. Permutations II

原文地址：https://www.cnblogs.com/siriusli/p/10386631.html