program MaxDistanceProgram;
{$mode objfpc}{$H+}
type
TIntArray = array of Integer;
{
Finds the maximum distance between two values in an array.
Distance = Abs(IndexA - IndexB)
Returns:
- Maximum distance if both values exist.
- -1 if one or both values are not found.
}
function MaxDistanceBetweenValues(const Arr: TIntArray;
Value1, Value2: Integer): Integer;
var
I: Integer;
First1, Last1: Integer;
First2, Last2: Integer;
Distance1, Distance2: Integer;
begin
First1 := -1;
Last1 := -1;
First2 := -1;
Last2 := -1;
{ Find first and last occurrences of both values }
for I := 0 to High(Arr) do
begin
if Arr[I] = Value1 then
begin
if First1 = -1 then
First1 := I;
Last1 := I;
end;
if Arr[I] = Value2 then
begin
if First2 = -1 then
First2 := I;
Last2 := I;
end;
end;
{ Check if both values were found }
if (First1 = -1) or (First2 = -1) then
Exit(-1);
{ Compare both extreme distances }
Distance1 := Abs(First1 - Last2);
Distance2 := Abs(First2 - Last1);
if Distance1 > Distance2 then
Result := Distance1
else
Result := Distance2;
end;
var
Arr: TIntArray;
Distance: Integer;
begin
Arr := TIntArray.Create(
2, 3, 7, 3, 3, 4, 8, 8, 8, 11, 9, 1, 3
);
Distance := MaxDistanceBetweenValues(Arr, 3, 8);
WriteLn('Maximum distance between 3 and 8: ', Distance);
end.
{
run:
Maximum distance between 3 and 8: 7
}
