Compilare: user.cpp: In function ‘int solve()’: user.cpp:75:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<exponents.size(); ++i) ~^~~~~~~~~~~~~~~~~ user.cpp: In function ‘void compute_primes()’: user.cpp:101:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; ok && j<primes.size() && primes[j] * primes[j] <= i; ++j) ~^~~~~~~~~~~~~~ user.cpp: In function ‘int solve()’: user.cpp:38:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:43:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp: In function ‘int main()’: user.cpp:109:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divisorgraph.in", "r", stdin); ^ user.cpp:110:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divisorgraph.out", "w", stdout); ^ user.cpp:115:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &tests); ^