Problems

Here's the list of problems that we have considered. See the additional list below for other problems of interest to us. The problem numbers are those that are found on the Online Judging site at the Universidad de Valladolid.

**Note:** According to the programming
contest rules, your programs must be written to read from the standard
input and write to standard output in order to be correctly accepted.

What makes a problem interesting (to us, at least)? Some problems we select here (or later) might involve:

- Use of mathematical techniques and known algorithms, such as dynamic programming, finding shortest paths in graphs, the Euclidean algorithm, etc.;
- Elementary (or maybe not-so-elementary) probabilistic analysis;
- Combinatorial functions and methods, such as binomial coefficients, Catalan numbers, the principle of inclusion/exclusion, etc.;
- Recursion (although this can often be reformulated in a non-recursive fashion);
- A method/class for handling big integers (such as the Java BigInteger class);
- A backtracking routine to find the solution (i.e. some guided trial-and-error, if you like);
- Ad hoc methods for the solution;
- Etc.

Could not connect to the database:

Access denied for user 'lupe'@'lxserver7.csc.liv.ac.uk' (using password: NO)

Access denied for user 'lupe'@'lxserver7.csc.liv.ac.uk' (using password: NO)