Compilare: user.cpp: In function ‘int main()’: user.cpp:19:18: warning: unused variable ‘j’ [-Wunused-variable] int n, m, i, j, x, y, ok, nod, grad_nod; ^ user.cpp:19:36: warning: unused variable ‘grad_nod’ [-Wunused-variable] int n, m, i, j, x, y, ok, nod, grad_nod; ^ user.cpp:16:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("3color.in","r",stdin); ^ user.cpp:17:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("3color.out","w",stdout); ^ user.cpp:22:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:24:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^