Compilare: main.cpp: In function 'int nrdiv(int)': main.cpp:83:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 83 | for (register int i = 0; i < primes.size() && primes[i] <= limit; ++i) | ~~^~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:100:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 100 | for (register int j = 0; j < primes.size() && primes[j] <= d; ++j) | ~~^~~~~~~~~~~~~~~