Compilare: user.cpp: In function ‘void df()’: user.cpp:19:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<v[x].size();j++) if (!fort[v[x][j].first]) ^ user.cpp:26:83: warning: left operand of comma operator has no effect [-Wunused-value] if ((rez[a]==rez[x]+b)&&(vec[a]>vec[x])) rez[a]+rez[x]+b,vec[a]=vec[x],c.push_back(a); ^ user.cpp: In function ‘int main()’: user.cpp:35:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("catun.in","r",stdin); ^ user.cpp:36:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("catun.out","w",stdout); ^ user.cpp:37:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&n,&m,&k); ^ user.cpp:38:84: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i=1;i<=k;i++) scanf("%d",&x),vec[x]=x,viz[x]=1,fort[x]=true,c.push_back(x); ^ user.cpp:41:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %lld",&x,&y,&cost); ^