Compilare: user.cpp: In function ‘void df(int, int, int)’: user.cpp:22: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:105: warning: comparison between signed and unsigned integer expressions user.cpp:73: warning: unused variable ‘z’ user.cpp:70: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:71: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:72: warning: ignoring return value of ‘int scanf(const char*, ...)’, 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:79: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result