Compilare: user.cpp: In function ‘int main()’: user.cpp:134: warning: comparison between signed and unsigned integer expressions user.cpp:137: warning: comparison between signed and unsigned integer expressions user.cpp:157: warning: comparison between signed and unsigned integer expressions user.cpp:159: warning: comparison between signed and unsigned integer expressions user.cpp:169: warning: comparison between signed and unsigned integer expressions user.cpp:170: warning: comparison between signed and unsigned integer expressions user.cpp:172: warning: comparison between signed and unsigned integer expressions user.cpp:187: warning: comparison between signed and unsigned integer expressions user.cpp:62: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:63: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:65: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:71: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result