Compilare: user.cpp: In function ‘void interv_upd(int, int, int)’: user.cpp:50: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:151: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:152: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:153: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:155: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:157: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:161: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result