This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<bits/stdc++.h>
#define fi first
#define se second
#define pitem item*
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
const int sq=350;
const int N=1e5+10;
pair<int,int> t[N][sq];
vi graf[N];
int ile[N],wsk[N],maxi[N];
bitset<N>byl,vis,vis2;
int t2[N];
int n,m,q;
vi tt;
int f(int x){
vis2[x]=1;
int ans=-1;
for(int i=0;i<tt.size();i++){
int v=tt[i];
if(!vis2[v]) continue;
for(auto u:graf[v]) maxi[u]=max(maxi[u],maxi[v]+1),vis2[u]=1;
if(!byl[v]) ans=max(ans,maxi[v]);
}
for(int i=1;i<=n;i++) vis2[i]=0,maxi[i]=0;
return ans;
}
void solve(){
cin>>n>>m>>q;
for(int i=0;i<m;i++){
int a,b;
cin>>a>>b;
graf[b].push_back(a);
ile[a]++;
}
vi curr;
for(int i=1;i<=n;i++) if(ile[i]==0) curr.push_back(i);
while(curr.size()){
int v=curr.back();
curr.pop_back();
tt.push_back(v);
for(auto u:graf[v]){
ile[u]--;
if(ile[u]==0) curr.push_back(u);
}
}
int pier=sqrt(n);
for(int i=tt.size()-1;i>=0;i--){
int v=tt[i];
for(auto u:graf[v]) wsk[u]=1;
for(int j=1;j<=pier;j++){
int maxi1=0,maxi2=0;
for(auto u:graf[v]){
while(wsk[u]<=pier and (byl[t[u][wsk[u]].fi] or !t[u][wsk[u]].fi)) wsk[u]++;
if(t[u][wsk[u]].fi!=0 and t[u][wsk[u]].se+1>maxi1) maxi1=t[u][wsk[u]].se+1,maxi2=t[u][wsk[u]].fi;
}
if(maxi1==0){
t[v][j]={v,0};
break;
}
t[v][j]={maxi2,maxi1};
byl[maxi2]=1;
}
for(int j=1;j<=pier;j++) byl[t[v][j].fi]=0;
}
for(int i=1;i<=q;i++){
int x,il;
cin>>x>>il;
for(int j=1;j<=il;j++){
int a;
cin>>a;
t2[j]=a;
byl[a]=1;
}
if(il<0){
int res=0;
for(int j=1;j<=pier;j++){
if(byl[t[x][j].fi] or !t[x][j].fi) continue;
res=t[x][j].se;
break;
}
cout<<(res==0?-1:res)<<"\n";
}else cout<<f(x)<<"\n";
for(int j=1;j<=il;j++) byl[t2[j]]=0;
}
}
int main(){
ios_base::sync_with_stdio(0),cin.tie(0);
solve();
}
Compilation message (stderr)
bitaro.cpp: In function 'int f(int)':
bitaro.cpp:21:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
21 | for(int i=0;i<tt.size();i++){
| ~^~~~~~~~~~
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