mergeSort

var mergeSort = function(array) {
  
  array = genArray(array);
  
  return sort(array);
  
}


var merge = function(arrayOne, arrayTwo) {
  var resultArray = [];
  var jPointer = 0;
  
  for (var i=0; i < arrayOne.length; i ++) {
    for (var j=jPointer; j < arrayTwo.length && arrayTwo[j] < arrayOne[i]; j++) {
      resultArray.push(arrayTwo[j]);
    }
    
    resultArray.push(arrayOne[i]);
    jPointer = j;
    
  }
  
  return resultArray;
  
}

var sort = function(array) {
  if (typeof array[0][0] === "number") {
    // console.log("we have reached the final stage: ", array);
    return merge(array[0],array[1]);
  } else {
    
    console.log("we have reached the second to last stage: ", array);
    return merge(sort(array[0]), sort(array[1]))
  }
  
}

var genArray = function(array) {
  if (array.length > 1) {
    return [genArray(array.slice(0, array.length/2)), genArray(array.slice(array.length/2))]
  } else {
    return array
  }
}