Compilare: user.cpp: In function ‘void Read()’: user.cpp:20:9: warning: unused variable ‘i’ [-Wunused-variable] int i,j; ^ user.cpp:20:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp: In function ‘void Solve()’: user.cpp:47:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<Step[i].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:84:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cobai.out","w",stdout); ^