Compilare: user.cpp: In function ‘void BF(int)’: user.cpp:12:149: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] void BF (int nr){int x,i; for (i=1; i<=n; ++i)D[i]=inf;D[loc[nr]]=0;q.push(loc[nr]);while (! q.empty()){x=q.front (); q.pop();for (i=0; i<v[x].size(); ++i)if (D[v[x][i].nod]>D[x]+v[x][i].cost) ^ user.cpp: In function ‘int main()’: user.cpp:19:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("ubuntzei.in", "r", stdin); ^ user.cpp:20:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("ubuntzei.out", "w", stdout); ^ user.cpp:21:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d", &n, &m, &k);loc[0]=1;for (i=1; i<=k; ++i)scanf ("%d", &loc[i]);loc[k+1]=n;for (i=1; i<=m; ++i){scanf ("%d%d%d", &x, &y, &c);E.nod=y; E.cost=c;v[x].push_back(E);E.nod=x; E.cost=c; ^ user.cpp:21:84: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d", &n, &m, &k);loc[0]=1;for (i=1; i<=k; ++i)scanf ("%d", &loc[i]);loc[k+1]=n;for (i=1; i<=m; ++i){scanf ("%d%d%d", &x, &y, &c);E.nod=y; E.cost=c;v[x].push_back(E);E.nod=x; E.cost=c; ^ user.cpp:21:145: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d", &n, &m, &k);loc[0]=1;for (i=1; i<=k; ++i)scanf ("%d", &loc[i]);loc[k+1]=n;for (i=1; i<=m; ++i){scanf ("%d%d%d", &x, &y, &c);E.nod=y; E.cost=c;v[x].push_back(E);E.nod=x; E.cost=c; ^