Compilare: user.cpp: In member function ‘bool cmp::operator()(std::pair<int, int>, std::pair<int, int>) const’: user.cpp:26: warning: suggest parentheses around ‘&&’ within ‘||’ user.cpp: In function ‘int main()’: user.cpp:56: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:57: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:61: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:64: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result