# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
390488 | iANikzad | Bitaro’s Party (JOI18_bitaro) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
using namespace std;
#define pb push_back
#define F first
#define S second
#define debug(x) cerr<<#x<<" :"<<x<<"\n"
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define FAST ios_base::sync_with_stdio(false), cin.tie(), cout.tie();
#define int long long
typedef long long ll;
typedef long double ld;
const int maxn = 5e5 + 7;
const int mod = 1e9 + 7;
const int INF = 1e9 + 7;
const int mlog = 20;
const int SQRT = 400;
vector<int> adj[maxn], rev[maxn];
int id[maxn], dp[maxn];
bool mark[maxn];
vector<pii> res[maxn];
int32_t main()
{
FAST;
int n, m, qq;
cin >> n >> m >> qq;
for(int i = 0; i < m; i++)
{
int u, v;
cin >> u >> v;
adj[u].pb(v);
rev[v].pb(u);
}
stack<int> st;
for(int u = 1; u <= n; u++)
{
for(int v : rev[u]) id[v] = 0;
for(int i = 0; i < SQRT; i++)
{
pii mx = {u, 0};
for(int v : rev[u])
{
while(id[v] < res[v].size() && mark[res[v][id[v]].F])
id[v]++;
if(id[v] < res[v].size() && res[v][id[v]].S + 1 > mx.S)
mx = {res[v][id[v]].F, res[v][id[v]].S + 1};
}
res[u].pb(mx);
mark[mx.F] = true;
st.push(mx.F);
if(mx.F == u) break;
else id[mx.F]++;
}
while(!st.empty()) mark[st.top()] = false, st.pop();
}
while(qq--)
{
int T, Y;
cin >> T >> Y;
for(int i = 0; i < Y; i++)
{
int x; cin >> x;
mark[x] = true;
st.push(x);
}
if(Y >= SQRT)
{
for(int i = 1; i <= n; i++) dp[i] = -INF;
dp[T] = 0;
int ans = -1;
if(!mark[T]) ans = 0;
for(int i = T-1; i >= 1; i--)
{
for(int v : adj[i]) dp[i] = max(dp[i], dp[v] + 1);
if(!mark[i]) ans = max(ans, dp[i]);
}
cout << ans << "\n";
}
else
{
int ans = -1;
for(auto p : res[T])
{
int v, w;
tie(v, w) = p;
if(!mark[v]) {
ans = w;
break;
}
}
cout << ans << "\n";
}
while(!st.empty()) mark[st.top()] = false,st.pop();
}
return 0;
}