Compilare: user.cpp: In function ‘int main()’: user.cpp:123:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("online.in","r",stdin); ^ user.cpp:124:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("online.out","w",stdout); ^ user.cpp:125:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n,&m); ^ user.cpp:134:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x,&y,&cost); ^ user.cpp:141:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &m); ^ user.cpp:144:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x,&y,&cost); ^ user.cpp: In function ‘void Prim()’: user.cpp:33:42: warning: ‘surs’ may be used uninitialized in this function [-Wmaybe-uninitialized] w.nod=nod; w.cost=a[nod][surs]; ^ user.cpp:41:48: warning: ‘nod’ may be used uninitialized in this function [-Wmaybe-uninitialized] dist[j]=a[nod][j]; sursa[j]=nod; ^ user.cpp: In function ‘int main()’: user.cpp:61:23: warning: ‘nod’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(it=L[x].begin();it!=L[x].end();++it) ^ user.cpp:71:20: note: ‘nod’ was declared here int minim=-INF,nod,cx=x,cy=y; ^