Compilare: user.cpp: In function ‘void executa(FILE*, FILE*)’: user.cpp:15:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &a, &b, &x, &y); ^ user.cpp: In function ‘int main()’: user.cpp:57:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^