Type
    TVectorType = LongInt;
    TVector = Record
        Size, Capacity : LongInt;
        Nodes : Pointer;
    End;
    PVectorType = ^TVectorType;

Var
    A : TVector;

Procedure InitVector(Var V : TVector);
Begin
    V.Size := 0;
    V.Capacity := 0;
    V.Nodes := Nil;
End;

Procedure PushBack(Var V : TVector; Element : TVectorType);
Var
    Elem: PVectorType;
Begin
    If V.Size = V.Capacity Then
    Begin
        If V.Capacity = 0 Then Inc(V.Capacity);
        Inc(V.Capacity, V.Capacity);
        V.Nodes := ReAllocMem(V.Nodes, V.Capacity * SizeOf(TVectorType));
    End;
    Elem := V.Nodes;
    Inc(Elem, V.Size);
    Elem^ := Element;
    Inc(V.Size);
End;

Procedure ShrinkToFit(Var V : TVector);
Begin
    V.Nodes := ReAllocMem(V.Nodes, V.Size * SizeOf(TVectorType));
    V.Capacity := V.Size;
End;

Function PopBack(Var V : TVector) : PVectorType;
Var
    X : PVectorType;
Begin
    Dec(V.Size);
    X := V.Nodes;
    Inc(X, V.Size);
    PopBack := X;
End;

Function VectorAt(Var V : TVector; Index : LongInt) : PVectorType;
Var
    X : PVectorType;
Begin
    X := V.Nodes;
    Inc(X, Index);
    VectorAt := X;
End;

Procedure PrintVector(Var V : TVector);
Var
    I : LongInt;
    Elem: PVectorType;
Begin
    WriteLn('Vector size is: ', V.Size);
    Elem := V.Nodes;
    For I := 0 To V.Size - 1 Do
    Begin
        Write(Elem^, ' ');
        Inc(Elem);
    End;
End;

Procedure FreeVector(Var V : TVector);
Begin
    FreeMem(V.Nodes);
End;

Begin
    InitVector(A);
    PushBack(A, 1);
    PushBack(A, 2);
    PushBack(A, -1);
    PushBack(A, -3);
    PushBack(A, -3);
    PushBack(A, -3);
    PushBack(A, -3);
    PushBack(A, -3);
    PushBack(A, -3);
    PushBack(A, -3);
    WriteLn(A.Capacity);
    ShrinkToFit(A);
    PushBack(A, -1);
    WriteLn(A.Capacity);
    VectorAt(A, 2)^ := 5;
    PrintVector(A);
    FreeVector(A);
End.