Password Entropy & strength Calculator

Built off of tests-always-included/password-strength. Included is version 1 of the calculator, please write me if you'd like to clean up the code and make it better. I want this to be fully community built.

This Calculates the relative strength of a password using several techniques. Primarily this relies on letter trigraphs, which check each set of 3 characters in a given password. This also calculates the entropy bits based on Claude Shannon's technique on determining the number of bits required to represent a set of characters and multiplying it by the length of the password and there's a check to see if a password is contained in a list of common passwords and as a bonus there's also a "Search Space" or (Total Possible Combinations) Calculator, inspired by GRC's Interactive Brute Force Password “Search Space” Calculator. You can toggle between the normal algorithm and GRC's algorithm and create custom scenarios. Took me forever to figure out how GRC was calculating their "Search Space Size" but happy to have figured it out. Live Demo

• The normal algorithm is:

Var characters = 10;
Var length = 5;

 Math.pow(characters, length);

and a symbol character set size of 32.

• GRC's algorithm is:

Var characters = 10;
Var length = 5;
Var lengthstatic = 5;

function GRC(length) 
{ 
  if(length < 1) 
  {
    return 0 ; 
  }
  if (length == 1)
  {
    return Math.pow(characters, lengthstatic); 
  }
  return Math.pow(characters, length - 1) + GRC(length - 1); 
}

and a symbol character set size of 33.