Compilare: user.cpp: In function ‘void primeNumbers(unsigned int)’: user.cpp:17:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 3; i <= n; i += 2) { ^ user.cpp:22:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = i*i; j <= n; j += i+i) { ^ user.cpp: In function ‘int main()’: user.cpp:67:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("streetcrypto.in", "r", stdin); ^ user.cpp:68:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("streetcrypto.out", "w", stdout); ^ user.cpp:71:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int T; scanf("%d", &T); ^ user.cpp:74:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int N; scanf("%d", &N); ^ user.cpp:79:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] long long x; scanf("%lld", &x); ^