Submission #630451

#	Time	Username	Problem	Language	Result	Execution time	Memory
630451		Ooops_sorry	Game (APIO22_game)	C++17	60 / 100	4010 ms	48816 KiB

game

#include<bits/stdc++.h>

using namespace std;

mt19937 rnd(51);

#define ll long long
#define pb push_back
#define ld long double

const int N = 3e5 + 10, INF = 1e9, K = 500;
int n, k, in_block[N], out_block[N], in[N], out[N], block[N];
bool used[N];
vector<int> g[N], gr[N];
bool cycle = 0;
set<int> need;

void dfs_block(int v) {
    if (v >= k && out_block[v] < in_block[v]) {
        cycle = 1;
    }
    if (v >= k && !used[v] && out_block[v] == in_block[v]) {
        need.insert(in_block[v]);
        block[v] = in_block[v];
        used[v] = 1;
    }
    for (auto to : g[v]) {
        if (in_block[v] > in_block[to]) {
            in_block[to] = in_block[v];
            dfs_block(to);
        }
    }
}

void zhfs_block(int v) {
    if (v >= k && out_block[v] < in_block[v]) {
        cycle = 1;
    }
    if (v >= k && !used[v] && out_block[v] == in_block[v]) {
        need.insert(in_block[v]);
        block[v] = in_block[v];
        used[v] = 1;
    }
    for (auto to : gr[v]) {
        if (out_block[v] < out_block[to]) {
            out_block[to] = out_block[v];
            zhfs_block(to);
        }
    }
}

void dfs(int v) {
    if (v >= k && out[v] <= in[v]) {
        cycle = 1;
    }
    for (auto to : g[v]) {
        if (block[v] == block[to] && in[v] > in[to]) {
            in[to] = in[v];
            dfs(to);
        }
    }
}

void zhfs(int v) {
    if (v >= k && out[v] <= in[v]) {
        cycle = 1;
    }
    for (auto to : gr[v]) {
        if (block[v] == block[to] && out[v] < out[to]) {
            out[to] = out[v];
            zhfs(to);
        }
    }
}

int add_teleporter(int u, int v) {
    if (max(u, v) < k) {
        if (u >= v) {
            cycle = 1;
        }
    } else {
        g[u].pb(v);
        gr[v].pb(u);
        if (in_block[v] < in_block[u]) {
            in_block[v] = in_block[u];
            dfs_block(v);
        }
        if (out_block[u] > out_block[v]) {
            out_block[u] = out_block[v];
            zhfs_block(u);
        }
        for (auto v : need) {
            for (int vert = v * K; vert < min(k, (v + 1) * K); vert++) {
                zhfs(vert);
                dfs(vert);
            }
        }
        if (block[v] == block[u] && in[v] < in[u]) {
            in[v] = in[u];
            dfs(v);
        }
        if (block[v] == block[u] && out[u] > out[v]) {
            out[u] = out[v];
            zhfs(u);
        }
    }
    return cycle;
}

void init(int n_, int k_) {
    n = n_, k = k_;
    for (int i = 0; i < n; i++) {
        in_block[i] = -INF, out_block[i] = INF;
        in[i] = -INF, out[i] = INF;
        block[i] = -(i + 1);
    }
    for (int i = 0; i < k; i++) {
        in_block[i] = out_block[i] = block[i] = i / K;
        in[i] = out[i] = i;
        if (i + 1 < k) {
            add_teleporter(i, i + 1);
        }
    }
}

#ifdef LOCAL

signed main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
#endif // LOCAL
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, m, k;
    cin >> n >> m >> k;
    vector<pair<int,int>> e(m);
    for (int i = 0; i < m; i++) {
        cin >> e[i].first >> e[i].second;
    }
    init(n, k);
    int i;
    for (i = 0; i < m; i++) {
        int res = add_teleporter(e[i].first, e[i].second);
        assert(res == 0 || res == 1);
        if (res == 1) {
            break;
        }
    }
    cout << i << endl;
    return 0;
}

#endif // LOCAL

• Subtask 1: 2 / 2
• Subtask 2: 10 / 10
• Subtask 3: 18 / 18
• Subtask 4: 30 / 30
• Subtask 5: 0 / 40