Compilare: user.cpp: In function ‘bool isstacked(std::vector<int>)’: user.cpp:20:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < seq.size(); ++ i) { ^ user.cpp: In function ‘int main()’: user.cpp:74:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &k); ^ user.cpp:79:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &output[i]); ^