Compilare: main.cpp: In function 'void fill_primes(std::vector<int>&)': main.cpp:12:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 3; i < PRIME_LIMIT; i+=2) ~~^~~~~~~~~~~~~ main.cpp:13:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 3; j*i < PRIME_LIMIT; j+=2) ~~~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:53:33: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d", &p, &n); ^ main.cpp:64:36: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d", &number, &k); ^