Using our sample string “abc”, lets say that we are going through all the permutations where the first letter is \\\"c”. Then, it should be clear that the letter in the 2nd and 3rd position can only ...

A permutation, also called an "arrangement number" or "order" is a rearrangement of the elements of an ordered list S into a one-to-one correspondence with S itself. A string of length n has n!