Compilare: user.cpp: In function ‘double kruskal(int)’: user.cpp:65:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(temp.size()==l-1) ^ user.cpp: In function ‘int main()’: user.cpp:81:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("desen.in","r",stdin); ^ user.cpp:82:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("desen.out","w",stdout); ^ user.cpp:84:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&N); ^ user.cpp:87:39: 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); ^