Compilare: main.cpp: In function 'void bkt(int, int)': main.cpp:24:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(it == v.size()) ~~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:55:37: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::vector<std::pair<long long int, long long int> >::size_type {aka long unsigned int}' [-Wformat=] fprintf(fout, "%d\n", ans.size()); ^