Compilare: user.cpp: In function ‘int find(std::pair<int, int>)’: user.cpp:19: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void read()’: user.cpp:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result