Compilare: main.cpp: In function 'void build(ull, ull)': main.cpp:25:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < prime.size() && prime[i] <= B; ++i) ~~^~~~~~~~~~~~~~ main.cpp:25:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < prime.size() && prime[i] <= B; ++i) main.cpp: In function 'int main()': main.cpp:64:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i <= nr[lastL]; ++i) ~~^~~~~~~~~~~~ main.cpp:46:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pinex.in", "r", stdin); ^ main.cpp:47:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pinex.out", "w", stdout); ^