Submission #567168

#	Time	Username	Problem	Language	Result	Execution time	Memory
567168		1zaid1	Bitaro’s Party (JOI18_bitaro)	C++14	14 / 100	2095 ms	27500 KiB

bitaro

#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define int long long
typedef long long ll;
const int M = 1e5 + 5, MOD = 1e9+7;
vector<int> node[M], inv[M], top;
int vis[M], in[M];
map<int, int> is;

void dfs1(int s) {
    vis[s] = true;
    for (int i:node[s]) if (!vis[i]) dfs1(i);
    top.push_back(s);
}

void dfs2(int s) {
    vis[s] = true;
    for (int i:inv[s]) if (!vis[i]) dfs2(i);
}

signed main() {
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    srand(time(0));
    
    int n, m, t;
    cin >> n >> m >> t;

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

    for (int i = 1; i <= n; i++) if (!vis[i]) dfs1(i);
    reverse(top.begin(), top.end());
    for (int i = 0; i < n; i++) in[top[i]] = i;

    while (t--) {
        int s, k;
        cin >> s >> k;

        for (int i = 1; i <= k; i++) {
            int a;
            cin >> a;

            is[a] = true;
        }

        for (int i = 1; i <= n; i++) vis[i] = 0;
        dfs2(s);

        vector<int> dp(n+1, 0);
        for (int i = in[s]; i >= 0; i--) {
            int x = top[i];
            if (!vis[x]) continue;
            for (int j:inv[x]) {
                dp[j] = max(dp[x]+1, dp[j]);
            }
        }

        int ans = -1;
        for (int i = 1; i <= n; i++) {
            if (!is[i] && vis[i]) {
                //cout << i << ' ';
                ans = max(ans, dp[i]);
            }
        } //cout << ": ";

        cout << ans << endl;
        is.clear();
    }

    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

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
*/

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