0046 - Permutations

[omrawal]

Description of the Problem

Given an array nums of distinct integers, return all the possible permutations. You can return the answer in any order.

Example 1:

Input: nums = [1,2,3]
Output: [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]
Example 2:

Input: nums = [0,1]
Output: [[0,1],[1,0]]
Example 3:

Input: nums = [1]
Output: [[1]]

Constraints:

1 <= nums.length <= 6
-10 <= nums[i] <= 10
All the integers of nums are unique.

Code

class Solution:
    
    def rec(self,sinput,index,ans):
        n=len(sinput)
        if(index==n-1):
            ans.append(sinput.copy())
            return 
        
        for i in range(index,n):
            sinput[i],sinput[index]=sinput[index],sinput[i]
            self.rec(sinput,index+1,ans)
            sinput[i],sinput[index]=sinput[index],sinput[i]
            
    
    
    def permute(self, nums: List[int]) -> List[List[int]]:
        ans=[]
        index=0
        self.rec(nums,index,ans)
        return ans

Link To The LeetCode Problem

LeetCode