Speed Tracker

program SpeedTracker;

uses sysutils;

var
  time1, time2: string;
  distance: integer;

function getDifference (stringPos, maxValue: integer; var carry: integer; t1, t2: string): integer;
var
  tempDiff: integer;
begin
  tempDiff := strtoint(copy(t2, stringPos, 2)) - strtoint(copy(t1, stringPos, 2)) - carry;
  carry := 0;
  if tempDiff < 0 then
    begin
      carry := (abs(tempDiff) div maxValue) + 1;
      tempDiff := maxValue + tempDiff;
    end;
  getDifference := tempDiff;
end;

function getAverageSpeed (t1, t2: string; dist: integer): integer;
var
  carry: integer;
  timeDifference: real;
begin
  carry := 0;
  timeDifference := getDifference(7, 60, carry, t1, t2) / 3600 + getDifference(4, 60, carry, t1, t2) / 60 + getDifference(1, 24, carry, t1, t2);
  getAverageSpeed := round(dist / timeDifference);
end;

begin
  write('Enter camera 1 time (HH:MM:SS): ');
  readln(time1);
  write('Enter camera 2 time (HH:MM:SS): ');
  readln(time2);
  write('Enter distance between cameras (miles): ');
  readln(distance);
  writeln('Average Speed: ', inttostr(getAverageSpeed(time1, time2, distance)));
  readln;
end.