Submission #1265992

#	Time	Username	Problem	Language	Result	Execution time	Memory
1265992		son2008	Bitaro’s Party (JOI18_bitaro)	C++20	14 / 100	526 ms	426064 KiB

bitaro

#include <bits/stdc++.h>
using namespace std;
#define ii pair<int, int>
#define fi first
#define se second
// #define int long long
#define ll long long
#define ld double
#define mp make_pair
#define lg2 30
#define iii pair<int, ii>
#define iiii pair<ii, ii>
#define base 29
#define eps 1e-8
#define MASK(i) (1LL << (i))
#define BIT(S, i) (((S) >> (i)) & 1)
int dx[] = {0LL, 0LL, 1, -1, 1, 1, -1, -1};
int dy[] = {1, -1, 0LL, 0LL, 1, -1, 1, -1};
const int maxn = 4e5 + 5, S = 316, inf = 1e9;
const int mod = 1e9 + 7;
int n, m, q, dist[maxn], flag[maxn];
vector<int> a[maxn];
int solvelon(int st)
{
    for (int i = 1; i <= n; i++)
        dist[i] = -inf;
    dist[st] = 0;
    int ans = -1;
    for (int i = st; i >= 1; i--)
    {
        for (int v : a[i])
        {
            dist[i] = max(dist[i], dist[v] + 1);
        }
    }
    for (int i = 1; i <= n; i++)
    {
        if (!flag[i])
            ans = max(ans, dist[i]);
    }
    return ans;
}
vector<ii> dp[maxn];
vector<ii> Merge(vector<ii> A, vector<ii> B)
{
    for (int i = 0; i < B.size(); i++)
    {
        B[i].fi++;
    }
    vector<ii> ans;
    if ((int)B.size() == 0)
        return A;
    int i = 0, j = 0;
    while (i < A.size() && j < B.size() && ans.size() < S)
    {
        if (A[i].fi > B[j].fi)
        {
            ans.push_back(A[i]);
            i++;
        }
        else
        {
            ans.push_back(B[j]);
            j++;
        }
    }
    while (i < A.size() && ans.size() < S)
    {
        ans.push_back(A[i]);
        i++;
    }
    while (j < B.size() && ans.size() < S)
    {
        ans.push_back(B[j]);
        j++;
    }
    return ans;
}
void prepare_nho()
{

    for (int i = 1; i <= n; i++)
    {
        if ((int)dp[i].size() < S)
            dp[i].push_back({0, i});
        for (int v : a[i])
        {
            dp[v] = Merge(dp[v], dp[i]);
        }
    }
}
int solvenho(int st)
{
    for (ii x : dp[st])
    {
        if (!flag[x.se])
            return x.fi;
    }
    return -1;
}
signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
#define task "task"
    if (fopen(task ".inp", "r"))
    {
        freopen(task ".inp", "r", stdin);
        freopen(task ".out", "w", stdout);
    }
    cin >> n >> m >> q;
    for (int i = 1; i <= m; i++)
    {
        int u, v;
        cin >> u >> v;
        a[u].push_back(v);
    }
    prepare_nho();
    while (q--)
    {
        int T, Y;
        cin >> T >> Y;
        vector<int> v;
        for (int i = 1; i <= Y; i++)
        {
            int x;
            cin >> x;
            v.push_back(x);
            flag[x] = 1;
        }
        if (Y >= S)
        {
            cout << solvelon(T) << '\n';
        }
        else
        {
            cout << solvenho(T) << '\n';
        }
        for (int x : v)
        {
            flag[x] = 0;
        }
    }
    cerr << endl
         << "TIME : " << clock() * 0.001 << "s" << endl;
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:109:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  109 |         freopen(task ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:110:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  110 |         freopen(task ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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