Compilare: user.cpp: In function ‘int main()’: user.cpp:10:9: warning: unused variable ‘f’ [-Wunused-variable] FILE *f = freopen("perm3.in", "r", stdin); ^ user.cpp:11:9: warning: unused variable ‘g’ [-Wunused-variable] FILE *g = freopen("perm3.out", "w", stdout); ^ user.cpp:13:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:15:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld", &x[i]); ^ user.cpp:19:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld", &y[i]); ^