Compilare: main.cpp: In function 'int main()': main.cpp:53:18: warning: variable 'sef' set but not used [-Wunused-but-set-variable] pair<int, int> sef = findSef(it.first); ^~~ main.cpp:62:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < comps.size() && i < K; ++i) ~~^~~~~~~~~~~~~~ main.cpp:36:29: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d", &N, &K); ^ main.cpp:39:30: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d", &x, &y); ^