Compilare: user.cpp: In function ‘int main()’: user.cpp:17:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(pos == Stack.size()) { ^ user.cpp:6:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("scmax.in", "r", stdin); ^ user.cpp:7:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("scmax.out", "w", stdout); ^