Compilare: user.cpp: In function ‘void update(int, int, int)’: user.cpp:16: warning: suggest parentheses around arithmetic in operand of ‘^’ user.cpp: In function ‘int query(int, int)’: user.cpp:27: warning: suggest parentheses around arithmetic in operand of ‘^’ user.cpp: In function ‘void read()’: user.cpp:43: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result user.cpp: In function ‘int main()’: user.cpp:101: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:102: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result