Submission #751294

#	Time	Username	Problem	Language	Result	Execution time	Memory
751294		Dan4Life	Bitaro’s Party (JOI18_bitaro)	C++17	100 / 100	1259 ms	86192 KiB

bitaro

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
const int mxN = (int)2e5+2;
const int B = 50;

int n, m, Q, a, b;
vector<int> adj[mxN], cur;
vector<array<int,2>> node[mxN];
int bad[mxN], vis[mxN], dis[mxN], dp[mxN];

int main() {
	cin >> n >> m >> Q;
	for(int i = 0; i < m; i++)
		cin >> a >> b, adj[b].pb(a);
	for(int i = 1; i <= n; i++, cur.clear()){
		for(auto j : adj[i]){
			for(auto [w,u] : node[j]){
				if(vis[u]==i) dis[u] = max(dis[u], w+1);
				else vis[u]=i, dis[u] = w+1, cur.pb(u);
			}
		}
		for(auto u : cur) node[i].pb({dis[u],u});
		node[i].pb({0,i}); sort(rbegin(node[i]),rend(node[i]));
		if(node[i].size()>B) node[i].erase(begin(node[i])+B,end(node[i]));
	}
	for(int q = 1; q <= Q; q++){
		int t, k, x, ans=-1; cin >> t >> k;
		for(int i = 0; i < k; i++) cin >> x, bad[x]=q;
		if(k<B){
			for(auto [w,u] : node[t]){
				if(bad[u]!=q){ ans=w; break; }
			}
		}
		else{
			fill(dp, dp+n+1, -1);
			for(int i = 1; i <= t; i++){
				if(bad[i]!=q) dp[i]=0;
				for(auto j : adj[i]) if(dp[j]!=-1) 
					dp[i] = max(dp[i],dp[j]+1);
			}
			ans = dp[t];
		}
		cout << ans << "\n";
	}
}

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 86 / 86