// time O(n*n!), dfs will calls n! times and each non-leaf node traverse list costs O(n) and leaf node copy a list to answer costs O(n) // space O(n*n!), because answer contains n! permutations and ...

Given a string S. The task is to print all permutations of a given string. You don't need to read input or print anything. Your task is to complete the function find_permutaion() which takes the ...