Compilare: user.cpp: In function ‘void add(int, int)’: user.cpp:43: warning: suggest parentheses around arithmetic in operand of ‘^’ user.cpp: In function ‘int query(int)’: user.cpp:49: warning: suggest parentheses around arithmetic in operand of ‘^’ user.cpp: In function ‘void getline()’: user.cpp:63: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result user.cpp: In function ‘int main()’: 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 ‘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 user.cpp:103: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result