Compilare: user.cpp: In function ‘int main()’: user.cpp:61:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (scanf("%d", &N); N; --N) { ^ user.cpp:63:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &operation, &value); ^