Compilare: user.cpp: In function ‘void divide(int, int)’: user.cpp:20:9: warning: unused variable ‘l1’ [-Wunused-variable] int l1,l2,mid,i,j; ^ user.cpp:20:12: warning: unused variable ‘l2’ [-Wunused-variable] int l1,l2,mid,i,j; ^ user.cpp: In function ‘int main()’: user.cpp:50:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cmap.in","r",stdin); ^ user.cpp:51:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cmap.out","w",stdout); ^ user.cpp:52:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:54:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&v[i].x,&v[i].y); ^