1procedure mergeSort(A, left, right)
2 if left < right then
3 mid ← (left + right) / 2
4 mergeSort(A, left, mid)
5 mergeSort(A, mid+1, right)
6 merge(A, left, mid, right)
7procedure merge(A, left, mid, right)
8 while i ≤ mid and j ≤ right do
9 if A[i] ≤ A[j] then copy A[i]
10 else copy A[j]
11 copy remaining elements