Compilare: user.cpp: In function ‘void did(int)’: user.cpp:39: warning: comparison between signed and unsigned integer expressions user.cpp:43: warning: comparison between signed and unsigned integer expressions user.cpp:44: warning: comparison between signed and unsigned integer expressions user.cpp:46: warning: comparison between signed and unsigned integer expressions user.cpp:49: warning: comparison between signed and unsigned integer expressions user.cpp:50: warning: comparison between signed and unsigned integer expressions user.cpp:61: warning: comparison between signed and unsigned integer expressions user.cpp:65: warning: comparison between signed and unsigned integer expressions user.cpp:66: warning: comparison between signed and unsigned integer expressions user.cpp:68: warning: comparison between signed and unsigned integer expressions user.cpp:71: warning: comparison between signed and unsigned integer expressions user.cpp:72: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:83: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:84: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result