Compilare: user.cpp: In function ‘int unite(int, int)’: user.cpp:16:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:21:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("disjoint.in","r",stdin); ^ user.cpp:22:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("disjoint.out","w",stdout); ^ user.cpp:23:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m1); ^ user.cpp:27:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&op,&v1,&v2); ^