Compilare: user.cpp: In function ‘int getMex(std::vector<int>)’: user.cpp:14:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v.size() && v[i] == i; ++i); ^ user.cpp: In function ‘int main()’: user.cpp:20:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bowling.in", "r", stdin); ^ user.cpp:21:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bowling.out", "w", stdout); ^