Submission #1096152

#	Time	Username	Problem	Language	Result	Execution time	Memory
1096152		Zero_OP	Bitaro’s Party (JOI18_bitaro)	C++14	14 / 100	205 ms	48984 KiB

bitaro

#include "bits/stdc++.h"

using namespace std;

#define sz(v) (int)v.size()

const int MAX = 1e5 + 5;
int SQRT = 350;

int n, m, q, dp[MAX], f[MAX];
vector<int> adj[MAX], rev[MAX];
bool bad[MAX], vis[MAX];
//only take B nodes
vector<int> S[MAX], tmpS;

bool better(int u, int v){
    return (dp[u] == dp[v] ? u < v : dp[u] > dp[v]);
}

void addTmpS(int u){
    if(!tmpS.empty() && tmpS.back() == u); else tmpS.push_back(u);
}

void insert(vector<int>& A, vector<int>& B){ //define A is larger set
    vector<int>().swap(tmpS);

    int i = 0, j = 0;
    while(i < sz(A) || j < sz(B)){
        if(sz(tmpS) == SQRT + 50) break;
        if(i == sz(A)) addTmpS(B[j++]);
        else if(j == sz(B)) addTmpS(A[i++]);
        else if(better(A[i], B[j])) addTmpS(A[i++]);
        else addTmpS(B[j++]);
    }

    swap(tmpS, A);
}

int dfsDP(int u){
    if(vis[u]) return dp[u];
    vis[u] = true;
    for(int v : adj[u]){
        dp[u] = max(dp[u], dfsDP(v) + 1);
    }
    return dp[u];
}

queue<int> qu;
void bfsAdj(int s){
    vis[s] = true;
    qu.push(s);

    while(!qu.empty()){
        int u = qu.front(); qu.pop();

        for(int v : adj[u]){
            insert(S[v], S[u]);
            if(!vis[v]){
                vis[v] = true;
                qu.push(v);
            }
        }
    }
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    cin >> n >> m >> q;
    for(int i = 0; i < m; ++i){
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        rev[v].push_back(u);
    }

    for(int i = n; i >= 1; --i){
        if(!vis[i]){
            dfsDP(i);
        }
    }

    SQRT = sqrt(n);

    for(int i = 1; i <= n; ++i){ S[i].push_back(i); }

    fill(vis + 1, vis + 1 +  n, false);
    for(int i = 1; i <= n; ++i){
        if(!vis[i]){
            bfsAdj(i);
        }
    }

//    for(int i = 1; i <= n; ++i){
//        cout << i << " : ";
//        for(int j : bestNodes[i]) cout << j << ' '; cout << '\n';
//    }

    while(q--){
        int t, y;
        cin >> t >> y;

        vector<int> nodes(y);
        for(int i = 0; i < y; ++i) cin >> nodes[i];

        for(int u : nodes) bad[u] = true;

        if(y > SQRT){
//            cout << "heavy\n";
            fill(f + 1, f + 1 + n, -1e9);
            f[t] = 0;

            for(int i = t; i > 0; --i){
                for(int j : rev[i]){
                    f[j] = max(f[j], f[i] + 1);
                }
            }

            int ans = -1;
            for(int i = t; i > 0; --i){
                if(!bad[i]) ans = max(ans, f[i]);
            }

            cout << ans << '\n';
        } else{
//            cout << "light\n";
            int ans = -1;
            for(int u : S[t]){
                if(!bad[u]){
                    ans = dp[u];
                    break;
                }
            }

            if(ans == -1){
                cout << ans << '\n';
            } else{
                ans -= dp[t];
                cout << ans << '\n';
            }
        }

        for(int u : nodes) bad[u] = false;
    }

    return 0;
}
/*


test 1 :
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

test 2 :
12 17 10
1 2
2 3
3 4
1 5
2 6
3 7
4 8
5 6
6 7
7 8
5 9
6 10
7 11
8 12
9 10
10 11
11 12
6 3 1 7 12
3 7 1 2 3 4 5 6 7
11 3 1 3 5
9 2 1 9
8 4 1 2 3 4
1 1 1
12 0
10 3 1 6 10
11 8 2 3 5 6 7 9 10 11
8 7 2 3 4 5 6 7 8

test 3 :
12 17 1
1 2
2 3
3 4
1 5
2 6
3 7
4 8
5 6
6 7
7 8
5 9
6 10
7 11
8 12
9 10
10 11
11 12
12 0
*/

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 0 / 86