Permutations Backtracking

permutations_backtracking.py

class Solution:

    def permute(self, nums: List[int]) -> List[List[int]]:
        result = []
        
        def backtracking(permutations, path, options):
            if len(path) == len(options):
                permutations.append(path[:])
            else:
                for option in options:
                    if option in path:
                        continue
                    path.append(option)
                    backtracking(permutations, path, options)
                    path.pop()
                
        backtracking(result, [], nums)
        
        return result