Compilare: user.cpp: In function ‘void compute()’: user.cpp:41:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sx.size(); ++i) ^ user.cpp:59:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (orig != B[i][j]) ^ user.cpp: In function ‘int main()’: user.cpp:69:27: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(OUT, "w", stdout); ^ user.cpp: In function ‘void read_data()’: user.cpp:23:25: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(IN, "r", stdin); ^