Compilare: user.cpp: In function ‘int adun(char*)’: user.cpp:21: warning: unused variable ‘n’ user.cpp: In function ‘int eval(cell)’: user.cpp:50: warning: NULL used in arithmetic user.cpp: In function ‘int main()’: user.cpp:61: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:62: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:65: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:68: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:69: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result