Compilare: user.cpp: In function ‘void Read()’: user.cpp:15:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&N,&M); ^ user.cpp:18:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&a,&b,&c); ^ user.cpp: In function ‘int main()’: user.cpp:64:32: 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:65:34: 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 ‘int selectmin()’: user.cpp:35:12: warning: ‘pzmin’ may be used uninitialized in this function [-Wmaybe-uninitialized] return pzmin; ^ user.cpp: In function ‘void Prim(int)’: user.cpp:34:20: warning: ‘pzmin’ may be used uninitialized in this function [-Wmaybe-uninitialized] used[pzmin] = 1; ^ user.cpp:28:20: note: ‘pzmin’ was declared here int mini = INF,pzmin; ^