Compilare: user.cpp: In function ‘void input()’: user.cpp:81:17: warning: left operand of comma operator has no effect [-Wunused-value] dominoes[i].first, dominoes[i].second; ~~~~~~~~~~~~^~~~~ user.cpp:81:36: warning: right operand of comma operator has no effect [-Wunused-value] dominoes[i].first, dominoes[i].second; ~~~~~~~~~~~~^~~~~~ user.cpp:78:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:80:59: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &dominoes[i].first, &dominoes[i].second); ^