Submission #1237616

#	Time	Username	Problem	Language	Result	Execution time	Memory
1237616		thuhienne	Bitaro’s Party (JOI18_bitaro)	C++20	0 / 100	14 ms	9032 KiB

bitaro

#include <bits/stdc++.h>
using namespace std;

#define FastIO ios_base::sync_with_stdio(0);cin.tie(nullptr);
#define MULTEST int t;cin >> t;while (t--) solve();
#define rf(__abc__) freopen(__abc__".inp","r",stdin);freopen(__abc__".out","w",stdout);

const int mod = 1e9 + 7;

long long pw(long long x,long long y) {
    if (y == 0) return 1;
    if (y % 2 == 0) {
        long long a = pw(x,y/2);
        return a*a%mod;
    } else {
        long long a = pw(x,y - 1);
        return a*x%mod;
    }
}

int add(int x,int y) {
    x += y;
    if (x >= mod) x -= mod;
    return x;
}

int subtract(int x,int y) {
    x -= y;
    if (x < 0) x += mod;
    return x;
}

int mul(long long x,int y) {
    x *= y;
    if (x >= mod) x %= mod;
    return x;
}

///Code goes here
const int can = 300;
int distinct = 0;

int n,m,q;
vector <int> adj[100009];

void input() {
    cin >> n >> m >> q;
    for (int i = 1;i <= m;i++) {
        int u,v;cin >> u >> v;
        adj[u].push_back(v);
    }
}
//dp
vector <pair<int,int>> dp[100001];
int exist[100009];
vector <pair<int,int>> mergesort(vector <pair<int,int>>& left,vector <pair<int,int>>& right) {
    vector <pair<int,int>> ret;
    int lpt = 0,rpt = 0;
    while (lpt < left.size() && rpt < right.size()) {
        if (left[lpt].first > right[rpt].first) {
            ret.push_back(left[lpt++]);
        } else {
            ret.push_back(right[rpt++]);
        }
    }
    for (;lpt < left.size();lpt++) ret.push_back(left[lpt]);
    for (;rpt < right.size();rpt++) ret.push_back(right[rpt]);
    return ret;
}
void predp() {
    for (int i = 1;i <= n;i++) {
        dp[i].push_back({-1,i});
        for (int j = 1;j < can;j++) dp[i].push_back({-1e9,n + 1});
    }
    for (int ver = 1;ver <= n;ver++) {
        for (int i = 0;i < can;i++) dp[ver][i].first++;
        for (auto des : adj[ver]) {
            //ver -> des
            vector <pair<int,int>> intermediate = mergesort(dp[ver],dp[des]);
            distinct++;
            int chosen = 0;
            for (auto value : intermediate) if (exist[value.second] != distinct) {
                exist[value.second] = distinct;
                dp[des][chosen] = value;
                chosen++;
                if (chosen == can) break;
            }
        }
    }
}
//query processing
bool visited[100009],busy[100009];
int dp2[100009];

int caldp(int node) {
    if (visited[node]) return dp2[node];
    visited[node] = 1;
    dp2[node] = (busy[node] ? -1e9 : 0);
    for (auto x : adj[node]) {
        dp2[node] = max(dp2[node],caldp(x) + 1);
    }
    return dp2[node];
}

void solve() {
    int root,num;cin >> root >> num;
    vector <int> record(num + 1);
    for (int i = 1;i <= num;i++) {
        cin >> record[i];
        busy[record[i]] = 1;
    }
    if (num >= can) {
        for (int i = 1;i <= n;i++) visited[i] = dp2[i] = 0;
        cout << caldp(root) << '\n';
    } else {
        for (int i = 0;i < can;i++) if (!busy[dp[root][i].second]) {
            cout << max(dp[root][i].first,-1) << '\n';
            break;
        }
    }
    for (int i = 1;i <= num;i++) busy[record[i]] = 0;
}

int main() {
    //rf("");
    FastIO
    //MULTEST

    //preprocessing
    input();
    predp();
    //answer queries
    while (q--) solve();
    return 0;
}

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