Merge Sort

 1 function merge_sort(array)
 2     
 3     // Assume power of 2 array size
 4     // Split using a pythonesque slice
 5     array_1 = merge_sort(array[len(array) / 2 : ])
 6     array_2 = merge_sort(array[ : len(array) / 2])
 7         
 8     array = merge(array_1, array_2)
 9 
10 
11 function merge(array_1, array_2)
12     
13     array = new_array(len(array_1) + len(array_2)) // Create new sortable array 
14     
15     counter_1 = 0
16     counter_2 = 0
17 
18     for i → len(array)
19 
20         if array_1[counter_1] < array_2[counter_2]
21             array[i] = array_1[counter_1]
22             counter_1 += 1
23         else
24             array[i] = array_2[counter_2]
25             counter_2 += 1
26     
27     return array