On this type of competition, we have about 3 or 4 hours (I don't know exactly) to code solutions of 4 problems. The comision then checks .exe files on the referent mashine. If program execute longer then some standard time (that is defined for every problem) you don't get points, even the solution is good. So important is the time limit on the running speed of my program.
As I alredy said, i know Pacal bether than c++, but it looks like algorithms in Pascal run slower.