Optimization: maximize the score
Some problems are harder than other's. They cannot be solved optimally in
reasonable time or it takes a while to execute the program for big sets of
tests. We can assign a score to programs solving such problems based on
several factors (e.g. execution time) so as to determine which one is the best.
The described problems may be used in contests as a way of determining the
winner. In some cases, several competitors may solve all classical problems
which would lead to a draw.
In case of a well designed optimization challenge, it is unusual for two or more users to get the
same result and therefore there is only one winner.