Submission #868552

#	Time	Username	Problem	Language	Result	Execution time	Memory
868552		lolismek	Bitaro’s Party (JOI18_bitaro)	C++14	100 / 100	1242 ms	324228 KiB

bitaro

#include <algorithm>
#include <iostream>
#include <vector>

#define pii pair <int, int>

using namespace std;

const int NMAX = 100000;
const int B = 250;

vector <int> adj[NMAX + 1];
vector <pii> t[NMAX + 1];

int from[NMAX + 1];
int dist[NMAX + 1];

bool no[NMAX + 1];

int main(){

    int n, m, q;
    cin >> n >> m >> q;

    for(int i = 1; i <= m; i++){
        int a, b;
        cin >> a >> b;
        adj[b].push_back(a);
    }

    for(int i = 1; i <= n; i++){
        vector <int> curr;
        for(int vec : adj[i]){
            for(pii x : t[vec]){
                if(from[x.second] == i){
                    dist[x.second] = max(dist[x.second], x.first + 1);
                }else{
                    from[x.second] = i;
                    dist[x.second] = x.first + 1;
                    curr.push_back(x.second);
                }
            }
        }

        t[i].push_back({0, i});
        for(int x : curr){
            t[i].push_back({dist[x], x});
        }
        sort(t[i].begin(), t[i].end(), greater <pii>());
        if((int)t[i].size() > B){
            t[i].erase(t[i].begin() + B, t[i].end());
        }
    }

    while(q--){
        int node, nr;
        cin >> node >> nr;

        vector <int> bad;
        for(int i = 1; i <= nr; i++){
            int x;
            cin >> x;
            bad.push_back(x);
            no[x] = true;
        }

        int ans = -1;
        if((int)bad.size() > B){
            vector <int> dp(n + 1, -1);

            dp[node] = 0;
            for(int i = node; i >= 1; i--){
                if(dp[i] != -1){
                    if(!no[i]){
                        ans = max(ans, dp[i]);
                    }
                    for(int vec : adj[i]){
                        dp[vec] = max(dp[vec], dp[i] + 1);
                    }
                }
            }
        }else{
            for(pii x : t[node]){
                if(!no[x.second]){
                    ans = x.first;
                    break;
                }
            }
        }

        cout << ans << '\n';

        for(int x : bad){
            no[x] = false;
        }
    }

    return 0;
}

/*
5 6 3
1 2
2 4
3 4
1 3
3 5
4 5
4 1 1
5 2 2 3
2 3 1 4 5
*/

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