Submission #1040160

#	Time	Username	Problem	Language	Result	Execution time	Memory
1040160		Sharky	Jail (JOI22_jail)	C++17	100 / 100	1287 ms	213584 KiB

jail

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

const int N = 120008;
const int LG = 19;

int n, m, sz[N], dep[N], node = 0, pr[N][LG], rt[N], tin[N], pa[N], timer = 0, leaf[N * 3], ls[N * 40], rs[N * 40], st[2], vis[N * 40], cyc = 0, col[N * 40];
vector<int> adj[N], g[N * 40];

void dfs(int u) {
    sz[u] = 1;
    for (int i = 1; i < LG; i++) pr[u][i] = pr[pr[u][i - 1]][i - 1];
    for (auto& v : adj[u]) {
        if (v == pr[u][0]) continue;
        pr[v][0] = u;
        dep[v] = dep[u] + 1;
        pa[v] = u;
        dfs(v);
        sz[u] += sz[v];
        if (sz[v] > sz[adj[u][0]]) swap(v, adj[u][0]);
    }
}

void dfs_hld(int u) {
    tin[u] = ++timer;
    for (int v : adj[u]) {
        if (v == pr[u][0]) continue;
        rt[v] = (v == adj[u][0] ? rt[u] : v);
        dfs_hld(v);
    }
}

int jump(int s, int di) {
    for (int i = LG - 1; i >= 0; i--) 
        if (di & (1 << i)) s = pr[s][i];
    return s;
}

int lca(int u, int v) {
    if (dep[u] > dep[v]) swap(u, v);
    v = jump(v, dep[v] - dep[u]);
    if (u == v) return u;
    for (int i = LG - 1; i >= 0; i--) {
        int ut = pr[u][i], vt = pr[v][i];
        if (ut != vt) u = ut, v = vt;
    }
    return pr[u][0];
}

void build(int l, int r, int id, bool up) {
    if (l == r) {
        leaf[l] = id;
        return;
    }
    int mid = (l + r) / 2;
    if (l != mid || !up) {
        ls[id] = ++node;
        build(l, mid, ls[id], up);
    } else ls[id] = leaf[l];
    if (mid + 1 != r || !up) {
        rs[id] = ++node;
        build(mid + 1, r, rs[id], up);
    } else rs[id] = leaf[r];
    if (!up) {
        g[id].push_back(ls[id]);
        g[id].push_back(rs[id]);
    } else {
        g[ls[id]].push_back(id);
        g[rs[id]].push_back(id);
    }
}

void update(int ql, int qr, int v, int l, int r, int id, bool up) {
    if (qr < l || r < ql) return;
    if (ql <= l && r <= qr) {
        if (!up) {
            // cout << "edge: " << v << "-->" << '[' << l << ", " << r << ']' << "\n";
            g[leaf[v]].push_back(id);
        } else {
            // cout << "edge: " << '[' << l << ", " << r << ']' << " --> " << v << "\n";
            g[id].push_back(leaf[v]);
        }
        return;
    }
    int mid = (l + r) / 2;
    update(ql, qr, v, l, mid, ls[id], up);
    update(ql, qr, v, mid + 1, r, rs[id], up);
}

void pti(int x, int l, int r) {
    update(l, r, x, 1, 2 * n + m, st[0], 0);
}

void itp(int x, int l, int r) {
    update(l, r, x, 1, 2 * n + m, st[1], 1);
}

void path(int x, int u, int v, bool b) {
    // cout << x << " " << u << " " << v << " " << b << "\n";
    for (; rt[u] != rt[v]; v = pa[rt[v]]) {
        if (dep[rt[u]] > dep[rt[v]]) swap(u, v);
        if (!b) pti(x + 2 * n, tin[rt[v]] + n, tin[v] + n);
        else itp(x + 2 * n, tin[rt[v]], tin[v]);
    }
    if (dep[u] > dep[v]) swap(u, v);
    if (!b) pti(x + 2 * n, tin[u] + n, tin[v] + n);
    else itp(x + 2 * n, tin[u], tin[v]);
}

bool DFS(int u) {
    col[u] = 1;
    for (int v : g[u]) {
        if (!col[v]) {
            if (DFS(v)) {
                cyc = 1;
                return true;
            }
        } else if (col[v] == 1) {
            cyc = 1;
            return true;
        }
    }
    col[u] = 2;
    return false;
}

void solve() {
    cin >> n;
    for (int i = 1; i < n; i++) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    cin >> m;
    rt[1] = pr[1][0] = 1;
    dfs(1); dfs_hld(1);
    st[0] = ++node;
    build(1, 2 * n + m, node, 0);
    st[1] = ++node;
    build(1, 2 * n + m, node, 1);
    for (int i = 1; i <= m; i++) {
        int u, v;
        cin >> u >> v;
        int x = lca(u, v);
        g[leaf[n * 2 + i]].push_back(leaf[tin[u]]);
        g[leaf[tin[v] + n]].push_back(leaf[n * 2 + i]);
        // cout << "edge: " << n * 2 + i << " --> " << tin[u] << '\n';
        // cout << "edge: " << tin[v] + n << " --> " << n * 2 + i << '\n';
        int d = max(dep[u], dep[v]) - dep[x] - 1;
        if (u != x) {
            path(i, pa[u], v, 1);
        } else {
            path(i, jump(v, d), v, 1);
        }
        if (v != x) {
            path(i, u, pa[v], 0);
        } else {
            path(i, u, jump(u, d), 0);
        }
    }
    // for (int i = 1; i <= node; i++) for (int j : g[i]) cout << i << " --> " << j << '\n';
    for (int i = 1; i <= node; i++) if (!col[i] && DFS(i)) break;
    cout << (cyc ? "No" : "Yes") << '\n';
    for (int i = 1; i <= n; i++) {
        sz[i] = dep[i] = rt[i] = tin[i] = pa[i] = 0;
        adj[i].clear();
        for (int j = 0; j < LG; j++) pr[i][j] = 0;
    }
    for (int i = 1; i <= n * 3; i++) leaf[i] = 0;
    for (int i = 1; i <= node; i++) {
        g[i].clear();
        ls[i] = rs[i] = col[i] = vis[i] = 0;
    }
    timer = cyc = node = st[0] = st[1] = 0;
}

int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    int q;
    cin >> q;
    while (q--) solve();   
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 16 / 16
• Subtask 4: 28 / 28
• Subtask 5: 12 / 12
• Subtask 6: 11 / 11
• Subtask 7: 23 / 23