Compilare: user.cpp: In function ‘void Solve_Kruskal()’: user.cpp:85:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned i=0; i<M && APM.size()<N-1;i++) ^ user.cpp:85:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned i=0; i<M && APM.size()<N-1;i++) ^ user.cpp: In function ‘void Read()’: user.cpp:69:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.in","r",stdin); ^ user.cpp:70:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&N,&M); ^ user.cpp:73:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&z); ^ user.cpp: In function ‘void Print()’: user.cpp:97:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.out","w",stdout); ^ user.cpp: In function ‘void Solve_Kruskal()’: user.cpp:80:12: warning: ‘cmp.Knoten::edge1’ may be used uninitialized in this function [-Wmaybe-uninitialized] Knoten cmp; ^ user.cpp:80:12: warning: ‘cmp.Knoten::edge2’ may be used uninitialized in this function [-Wmaybe-uninitialized] user.cpp:80:12: warning: ‘cmp.Knoten::cost’ may be used uninitialized in this function [-Wmaybe-uninitialized]