Submission #1161693

#	Time	Username	Problem	Language	Result	Execution time	Memory
1161693		Mher777	Railway (BOI17_railway)	C++20	100 / 100	74 ms	29920 KiB

railway

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <iomanip>
#include <array>
#include <string>
#include <algorithm>
#include <cmath>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <bitset>
#include <list>
#include <iterator>
#include <numeric>
#include <complex>
#include <utility>
#include <random>
#include <cassert>
#include <fstream>
using namespace std;
mt19937 rnd(time(nullptr));

/* -------------------- Typedefs -------------------- */

typedef int itn;
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef float fl;
typedef long double ld;

/* -------------------- Usings -------------------- */

using vi = vector<int>;
using vll = vector<ll>;
using mii = map<int, int>;
using mll = map<ll, ll>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

/* -------------------- Defines -------------------- */

#define ff first
#define ss second
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define mpr make_pair
#define yes cout<<"Yes\n"
#define no cout<<"No\n"
#define all(x) (x).begin(), (x).end()
#define USACO freopen("feast.in", "r", stdin); freopen("feast.out", "w", stdout);

/* -------------------- Constants -------------------- */

const int dx[8] = { -1, 0, 1, 0, -1, -1, 1, 1 };
const int dy[8] = { 0, -1, 0, 1, -1, 1, -1, 1 };
const int MAX = int(1e9 + 5);
const ll MAXL = ll(1e18) + 5ll;
const ll MOD = ll(1000000007);
const ll MOD2 = ll(998244353);

/* -------------------- Functions -------------------- */

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

void precision(int x) {
    cout.setf(ios::fixed | ios::showpoint);
    cout.precision(x);
}

ll gcd(ll a, ll b) {
    if (a == 0 || b == 0) return(max(a, b));
    while (b) {
        a %= b;
        swap(a, b);
    }
    return a;
}

ll lcm(ll a, ll b) {
    return a / gcd(a, b) * b;
}

ll range_sum(ll a, ll b) {
    if (a > b) return 0ll;
    ll dif = a - 1, cnt = b - a + 1;
    ll ans = ((b - a + 1) * (b - a + 2)) / 2;
    ans += ((b - a + 1) * dif);
    return ans;
}

string dec_to_bin(ll a) {
    string s = "";
    for (ll i = a; i > 0; ) {
        ll k = i % 2;
        i /= 2;
        char c = k + 48;
        s += c;
    }
    if (a == 0) {
        s = "0";
    }
    reverse(all(s));
    return s;
}

ll bin_to_dec(string s) {
    ll num = 0;
    for (int i = 0; i < s.size(); i++) {
        num *= 2ll;
        num += (s[i] - '0');
    }
    return num;
}

ll factorial_by_mod(ll n, ll mod) {
    ll ans = 1;
    ll num;
    for (ll i = 1; i <= n; ++i) {
        num = i % mod;
        ans *= num;
        ans %= mod;
    }
    return ans;
}

bool isPrime(ll a) {
    if (a == 1) return false;
    for (ll i = 2; i * i <= a; i++) {
        if (a % i == 0) return false;
    }
    return true;
}

ll binpow(ll a, ll b) {
    if (!a) return 0;
    ll ans = 1;
    while (b) {
        if (b & 1) {
            ans *= a;
        }
        b >>= 1;
        a *= a;
    }
    return ans;
}

ll binpow_by_mod(ll a, ll b, ll mod) {
    if (!a) return 0;
    ll ans = 1;
    while (b) {
        if (b & 1) {
            ans *= a;
            ans %= mod;
        }
        b >>= 1;
        a *= a;
        a %= mod;
    }
    return ans;
}

/* -------------------- Solution -------------------- */

const int N = 100005, M = 30;
vector<pii> g[N];
int id[N], id_rev[N], tin[N], tout[N], up[N][M], dep[N], used[N], till[N], cnt[N];
pii p[N];
int n, q, k, cur, timer, lg;

void dfs(int index = 0, int u = 1, int par = 1) {
    p[u] = { par, index };
    id[u] = ++cur;
    id_rev[cur] = u;
    tin[u] = ++timer;
    up[u][0] = par;
    for (int l = 1; l <= lg; ++l) {
        up[u][l] = up[up[u][l - 1]][l - 1];
    }
    for (auto to : g[u]) {
        if (to.ff == par) continue;
        dep[to.ff] = dep[u] + 1;
        dfs(to.ss, to.ff, u);
    }
    till[u] = cur;
    tout[u] = ++timer;
}

bool upper(int x, int y) {
    return tin[x] <= tin[y] && tout[x] >= tout[y];
}

int lca(int x, int y) {
    if (upper(x, y)) return x;
    if (upper(y, x)) return y;
    for (int l = lg; l >= 0; --l) {
        if (!upper(up[x][l], y)) {
            x = up[x][l];
        }
    }
    return up[x][0];
}

void slv() {
    cin >> n >> q >> k;
    lg = log2(n);
    for (int i = 1; i <= n - 1; ++i) {
        int x, y;
        cin >> x >> y;
        g[x].pub({ y,i });
        g[y].pub({ x,i });
    }
    dfs();
    while (q--) {
        int m;
        cin >> m;
        vi v1, ch;
        vector<int> v;
        for (int i = 0; i < m; ++i) {
            int x;
            cin >> x;
            x = id[x];
            v1.pub(x);
            v.pub(x);
            used[x] = 1;
        }
        sort(all(v1));
        for (int i = 1; i < m; ++i) {
            int x = id[lca(id_rev[v1[i]], id_rev[v1[i - 1]])];
            if (used[x]) continue;
            used[x] = 1;
            v.pub(x);
        }
        sort(all(v));
        used[v[0]] = 0;
        for (int i = 1; i < (int)v.size(); ++i) {
            used[v[i]] = 0;
            ++cnt[id_rev[v[i]]];
            int from = lca(id_rev[v[i]], id_rev[v[i - 1]]);
            --cnt[from];
        }
    }
    vector<pii> v;
    for (int i = 1; i <= n; ++i) {
        v.pub({ -dep[i], i });
    }
    sort(all(v));
    vi ans;
    for (auto elem : v) {
        int u = elem.ss;
        int par = p[u].ff, ind = p[u].ss;
        cnt[par] += cnt[u];
        if (cnt[u] >= k) {
            ans.pub(ind);
        }
    }
    sort(all(ans));
    cout << (int)ans.size() << '\n';
    for (auto elem : ans) {
        cout << elem << " ";
    }
}

void cs() {
    int tstc = 1;
    //cin >> tstc;
    while (tstc--) {
        slv();
    }
}

void precalc() {
    return;
}

int main() {
    fastio();
    precalc();
    //precision(0);
    cs();
    return 0;
}

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