southwestSort

southwestSort.js

var letters = ["q","w","e","r","t","y","u","i","o","p","a","s","d","f","g","h","j","k","l","z","x","c","v","b","n","m"];

function southwestSort( arr ) {
  var a = arr.slice( 0, Math.floor(arr.length / 3) );
  var b = arr.slice( Math.floor(arr.length / 3), Math.floor(arr.length / 3)*2 );
  var c = arr.slice( Math.floor(arr.length / 3)*2, arr.length );
  
  return a.sort().concat(b.sort()).concat(c.sort());
}

southwestSort( letters );
// [ "e","i","q","r","t","u","w","y","a","d","f","g","h","o","p","s","b","c","j","k","l","m","n","v","x","z" ]

Fun fact: This is how the Dvorak keyboard was invented.

this function smells as bloated as american airlines, dave.

function southwestSort(a){return a.concat.apply([],[0,1,2].map(function(i){return a.slice(i*a.length/3,++i*a.length/3,).sort()}))}