|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|

|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|+|_|_|

|_|_|_|_|_|_|_|_|_|_|_|_|+|_|_|_|_|+|_|_|

|_|_|_|_|_|_|_|_|_|_|_|_|+|_|_|_|_|+|+|_|

|_|_|+|_|_|_|_|_|_|_|_|_|+|_|_|_|_|+|+|_|

|_|_|+|_|_|_|_|_|_|_|_|_|+|_|_|_|_|+|+|+|

for each x <- input:
if A[x-(-1000)] == true
return "there are duplicates"
else
A[x-(-1000)] = true

mergesort(A,start,end){
____if((end - start) == 1) {
________rv = new Array[1];
________rv[0] = A[start];
____}
____else if((end - start) == 0) {
________rv = null;
____}
____else {
________rv = merge(mergesort(A,start,floor((start+end)/2)),mergesort(A,ceiling((start+end)/2),end));
____}
____return rv;
}
.
.
.
merge(A,B) {
____i = ia = ib = 0;
____C = new Array[A.size() + B.size()];
____while((ia < A.size()) && (ib < B.size())) {
________if(A[ia] < B[ib]) {
____________C[i] = A[ia];
____________ia++;
________}
________else {
____________C[i] = B[ib];
____________ib++;
________}
________i++;
____}
____return concat(C,&A[ia],&B[ib]);
}