Compilare: user.cpp: In function ‘void df(int, int, int)’: user.cpp:16: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:77: warning: unused variable ‘j’ user.cpp:75: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:76: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:78: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:82: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:90: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result