Hello all. Today , I participated in a contest with problems from the Croatian Olympiad in Informatics. The relevant contest environment is here. I had a perfect solution for the 3rd problem , and I was able to solve the first part ( finding the number of different values of the shortest path) of the first problem.My backtracking solution for the 2nd turned out to be buggy and scored 0. Since they take too long to publish the results along with codes and solutions on COCI , I'd appreciate if anyone who has participated ( specially those solving many tasks perfectly) can explain his algorithmic approaches for solving the problems.Thanks!