Compilare: main.cpp: In function 'long long int solve(long long int, long long int)': main.cpp:41:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (primes[k] <= 1ll * lim && b > 1 && k < primes.size()) ~~^~~~~~~~~~~~~~~ main.cpp:61:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.size(); i++) ~~^~~~~~~~~~~~