These are chat archives for camperbot/bonfire-truncate-a-string

29th
Apr 2016
Coryphaeus
@cvdeby
Apr 29 2016 17:04
help repeat please
CamperBot
@camperbot
Apr 29 2016 17:04
no wiki entry for: no repeat please
Coryphaeus
@cvdeby
Apr 29 2016 17:05
help no repeats
CamperBot
@camperbot
Apr 29 2016 17:05

:point_right: algorithm no repeats please [wiki]

Problem Explanation:

  • This task requires us to look at each possible permutation of a string. This is best done using a recursion function. Being able to build a function which collects all permutations of a string is a common interview question, so there is no shortage of tutorials out there on how to do this, in many different code languages.
  • This task can still be daunting even after watching a tutorial. You will want to send each new use of the function 3 inputs: 1. a new string (or character array) that is being built, 2. a position in your new string that's going to be filled next, and 3. an idea of what characters (more specifically positions) from the original string have yet to be used. The pseudo code will look something like this:

    ```
    var str = ???;
    perm(current position in original string, what's been used in original string, current string build thus far){
    if(current string is finished) {
    print current string;
    }else{
    for(var i = 0; i < str.length; i++) {

    if(str[i] has not been used) {
      put str[i] into the current position;
      mark str[i] as used
      perm(current position in original string, what's been used in original string, current string build thus far)
      unmark str[i] as used because another branch in the tree for i + 1 will still likely use it;
    }

    }
    }
    }
    :pencil: read more about algorithm no repeats please on the FCC Wiki