제출 #790498

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
790498		VMaksimoski008	Railway (BOI17_railway)	C++14	0 / 100	91 ms	28404 KiB

railway

#include <bits/stdc++.h>

#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define uniq(x) x.erase(unique(all(x)), x.end())
#define rall(x) x.rbegin(), x.rend()
#define mp make_pair
#define vec vector

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using str = string;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

const int mod = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e5 + 5;

void setIO() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}

vec<vec<pii> > graph;
vec<int> euler, in, out;
vec<int> depth;
vec<int> edges;
vec<vec<int> > up;
int timer = 0;

void resize(int n) {
    in.resize(n+1);
    out.resize(n+1);
    graph.resize(n+1);
    depth.resize(n+1);
    up.resize(n+1, vec<int>(LOG));
    edges.resize(n+1);
}

void dfs(int u, int p) {
    euler.pb(u);
    in[u] = ++timer;

    for(int i=1; i<LOG; i++)
        up[u][i] = up[ up[u][i-1] ][i-1];

    for(pii &v : graph[u]) {
        if(v.first == p) continue;
        depth[v.first] = depth[u] + 1;
        up[v.first][0] = u;
        edges[v.first] = v.second;
        dfs(v.first, u);
    }

    euler.pb(u);
    out[u] = timer;
}

int jmp(int x, int d) {
    for(int j=LOG-1; j>=0; j--)
        if(d & (1 << j)) x = up[x][j];
    return x;
}

int get_lca(int a, int b) {
    if(depth[a] < depth[b]) swap(a, b);

    a = jmp(a, depth[a] - depth[b]);
    if(a == b) return a;
    for(int j=LOG-1; j>=0; j--)
        if(up[a][j] != up[b][j])
            a = up[a][j], b = up[b][j];

    return up[a][0];
}

bool cmp(int a, int b) {
    return (in[a] < in[b]);
}

struct BIT {
    int n;
    vector<ll> tree;

    BIT(int n) : n(n+5), tree(n+5) {}

    void update(int p, int v = 1) {
        for(p++; p<n; p+=p&-p) tree[p] += v;
    }

    ll query(int p) {
        ll ans = 0;
        for(p++; p>0; p-=p&-p) ans += tree[p];
        return ans;
    }

    ll query(int a, int b) {
        return query(b) - query(a);
    }
};

int32_t main() {
    setIO();

    int n, m, k;
    cin >> n >> m >> k;
    resize(n);

    for(int i=0; i<n-1; i++) {
        int a, b;
        cin >> a >> b;
        graph[a].push_back({ b, i });
        graph[b].push_back({ a, i });
    }

    dfs(1, 0);
    BIT bit(n+1);
    while(m--) {
        int x;
        cin >> x;
        vector<int> list(x);
        for(int i=0; i<x; i++)
            cin >> list[i];
        sort(list.begin(), list.end() - 1, cmp);
        list.pb(list[0]);
        for(int i=0; i<x; i++) {
            int lca = get_lca(list[i], list[i+1]);
            bit.update(in[list[i]]);
            bit.update(in[list[i+1]]);
            bit.update(in[lca], -2);
        }
    }
    
    vec<int> ans;
    for(int i=2; i<=n; i++)
        if(bit.query(in[i], out[i]) >= 2 * k)
            ans.pb(edges[i]);

    cout << sz(ans) << '\n';
    sort(all(ans));
    for(int &x : ans) cout << x + 1 << ' ';
    return 0;
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 7
• Subtask 4: 0 / 29
• Subtask 5: 0 / 16
• Subtask 6: 0 / 25