Compilare: user.cpp: In function ‘int backy(int)’: user.cpp:14: warning: array subscript has type ‘char’ user.cpp: In function ‘int main()’: user.cpp:50: warning: format ‘%lld’ expects type ‘long long int’, but argument 2 has type ‘int’ user.cpp:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result