Compilare: user.cpp: In function ‘int main()’: user.cpp:95: warning: suggest explicit braces to avoid ambiguous ‘else’ user.cpp:113: warning: comparison between signed and unsigned integer expressions user.cpp:139: warning: comparison between signed and unsigned integer expressions user.cpp:121: warning: unused variable ‘res’ user.cpp:60: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:61: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:64: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:67: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:63: warning: ‘st’ may be used uninitialized in this function