I've been using a quicksort function to sort my stringlists, but as an exercise I wanted to try and code an heapsort function too. Unfortunately it does not work and I can't understand why. The utility functions I use work (because I use them in the quicksort script too and trying both on a list the quicksort one works and the other doesn't)
{------------------------------------------------------------------------------}
Procedure Heapify(AList : TStringList; N, Root : Integer);
Var
Max, L, R : Integer;
Begin
Max := Root;
L := (2 * Root) 1;
R := (2 * Root) 2;
If (L < N) And (ListSort(AList, Max, L) < 0 {function to compare strings, read as List[L]>List[Max]}) Then Max := L;
If (R < N) And (ListSort(AList, Max, R) < 0) Then Max := R;
If Max <> Root Then
Begin
ExchangeItems(AList, Root, Max); {Function to swap strings}
Heapify(AList, N, Max);
End;
End;
{------------------------------------------------------------------------------}
Procedure HeapSortStringList(AList : TStringList);
Var
I : Integer;
Begin
For I := (AList.Count / 2) - 1 DownTo 0 Do Heapify(AList, AList.Count, I);
For I := AList.Count - 1 DownTo 1 Do
Begin
ExchangeItems(AList, I, 0);
Heapify(AList, I, 0);
End;
End;
{------------------------------------------------------------------------------}
CodePudding user response:
How did you compile this code?
Note that compiler gives us message:
[dcc32 Error] Unit2.pas(175): E2010 Incompatible types: 'Integer' and 'Extended'
(AList.Count / 2)
should be (AList.Count div 2)
for integers
After this correction code becomes working.