Compilare: user.cpp: In function ‘int main()’: user.cpp:214:14: warning: unused variable ‘y’ [-Wunused-variable] int x = 0, y = 0; ^ user.cpp:215:9: warning: unused variable ‘l’ [-Wunused-variable] node *l, *mid, *r; ^ user.cpp:215:13: warning: unused variable ‘mid’ [-Wunused-variable] node *l, *mid, *r; ^ user.cpp:215:19: warning: unused variable ‘r’ [-Wunused-variable] node *l, *mid, *r; ^ user.cpp:220:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ user.cpp:226:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ user.cpp:232:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^