No Repeats WIP

gistfile1.txt

function permAlone(str) {
str = str.split('');
// find total permutations, or (str.length!)
  
// subtract possible pair perms
//    n = # of unique letters
//    x = # of each repeated letter
//  pair perms = n! * x!
var len = str.length; 
var letters = uniqueLetters(str);
var n = letters.length;
  
if (n===1) {
  return 0;
}
console.log(n);
  
  
var allPerm = factorial(len);
var pairPerm = factorial(n) * factorial(len-n);
  
  return allPerm - pairPerm;

function factorial(num) {
  if (num === 0) return 0;
  if (num === 1) return 1;
  else return num*factorial(num-1);
}

function uniqueLetters(str) {
  var letters = [];
  str.forEach(function(letter, index) {
    if (letters.indexOf(letter) < 0) {
      letters.push(letter);
    }
  });
  return letters;
}
  


}

permAlone('aab');