Compilare: user.cpp: In function ‘void schimb()’: user.cpp:46: warning: comparison between signed and unsigned integer expressions user.cpp:51: warning: comparison between signed and unsigned integer expressions user.cpp:59: warning: comparison between signed and unsigned integer expressions user.cpp:64: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:73: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:74: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:75: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:76: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:81: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result