Compilare: user.cpp: In function ‘void built(int)’: user.cpp:25: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void sterge(int)’: user.cpp:54: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int ap_cuv(int)’: user.cpp:75: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int prefix_max(int)’: user.cpp:96: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:113: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:114: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result