46. Permutations - LeetCode Solution

class Solution:
    def permute(self, nums: List[int]) -> List[List[int]]:
        ans = []
        
        def trav(data, i, length):
            if i ==length:
           
                ans.append(data.copy())
            else:
                for j in range(i, length):
                    data[i], data[j] =  data[j], data[i]
                    trav(data, i+1, length)
                    data[i], data[j] = data[j], data[i]
        
        trav(nums, 0, len(nums))
        return ans