Compilare: user.cpp: In function ‘int main()’: user.cpp:27: warning: unused variable ‘nh’ user.cpp: In function ‘void readData(int&, int&, NOD**)’: user.cpp:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void writeData(int*, int)’: user.cpp:150: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result