Compilare: main.cpp: In function 'int main()': main.cpp:35:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1; j < Primes.size (); ++ j) { ~~^~~~~~~~~~~~~~~~ main.cpp:50:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1; j < Primes.size (); ++ j) { ~~^~~~~~~~~~~~~~~~ main.cpp:55:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < Primes.size (); ++ i) { ~~^~~~~~~~~~~~~~~~