Submission #1293614

#	Time	Username	Problem	Language	Result	Execution time	Memory
1293614		nhmktu	Bitaro’s Party (JOI18_bitaro)	C++17	100 / 100	1801 ms	411408 KiB

bitaro

#include <bits/stdc++.h>
#define ll long long
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define ROF(i,a,b) for(int i=a;i>=b;i--)
#define pi pair<int,int>
#define pii pair<int,pi>
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(), x.end()
#define sz(a) (int) a.size()
#define endl '\n'
#define data "JOI18_bitaro"

using namespace std;
const ll linf = 1e18;
const int inf = 1e9;
const int MOD = 1e9 + 7, N = 1e5;
const int BLOCK = 320;

void add(int &a, int b)
{
    a += b;
    if(a>=MOD)
        a-=MOD;
    if(a<0)
        a += MOD;
}

int modulo(int x)
{
    if(x<=1)
        return 1;
    return (MOD - MOD/x) * modulo(MOD/x) % MOD;
}

int mul(int a, int b)
{
    return (1ll *a%MOD * b%MOD) % MOD;
}

int n, m, q;
vector<int> adj[N+3];
vector< pi > dist[N+3];

void inp(void)
{
    cin >> n >> m >> q;
    FOR(i, 1, m)
    {
        int u, v; cin >> u >> v;
        adj[v].pb(u);
    }
}

void solve(void)
{
    FOR(u, 1, n)
    {
        dist[u].pb({0, u});
        vector<int> pre(n+3, -1);
        vector<int> qu;

        FOR(i, 0, sz(adj[u]) -1)
        {
            int v = adj[u][i];
            FOR(j, 0, sz(dist[v]) -1)
            {
                int dv  = dist[v][j].fi;
                int idx = dist[v][j].se;

                if(pre[idx] == -1)
                {
                    qu.pb(idx);
                    pre[idx] = dv + 1;
                }
                else
                    pre[idx] = max(pre[idx], dv + 1);
            }
        }

        FOR(i, 0, sz(qu) - 1)
        {
            int idx = qu[i];
            dist[u].pb({pre[idx], idx});
        }

        sort(all(dist[u]), greater<pi>());
        while(sz(dist[u]) > BLOCK) dist[u].pop_back();
    }
    vector<bool> bussy(n+3, 0);

    FOR(_, 1, q)
    {
        int t, y; cin >> t >> y;
        vector<int> V;
        FOR(i, 1, y)
        {
            int x; cin >> x;
            bussy[x] = 1;
            V.pb(x);
        }

        int ans = -1;
        if(y >= BLOCK)
        {
            vector<int> dp(n+3, -1);
            dp[t] = 0;
            ROF(u, t, 1)
            {
                if(dp[u] == -1) continue;
                FOR(i, 0, sz(adj[u]) -1)
                {
                    int v = adj[u][i];
                    dp[v] = max(dp[v], dp[u] + 1);
                }
                if(bussy[u]) continue;
                ans = max(ans, dp[u]);
            }
        }
        else
        {
            FOR(i, 0, sz(dist[t]) -1)
            {
                int du = dist[t][i].fi;
                int idx = dist[t][i].se;
                if(bussy[idx]) continue;
                ans = max(ans, du);
            }

        }

        cout << ans << '\n';
        FOR(i, 0, y - 1) bussy[V[i]] = 0;
    }
}

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

    if(fopen(data".inp", "r"))
    {
        freopen(data".inp","r",stdin);
        freopen(data".out","w",stdout);
    }

    inp();
    solve();
    return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:145:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  145 |         freopen(data".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:146:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  146 |         freopen(data".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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