제출 #1068552

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1068552		TheQuantiX	통행료 (IOI18_highway)	C++17	51 / 100	236 ms	34616 KiB

highway

#include <bits/stdc++.h>
#include "highway.h"

using namespace std;
using ll = long long;

constexpr ll INF = 1000000000000000000LL;

ll n, m, q, k, x, y;
vector< pair<ll, ll> > G[90000];
vector<ll> ord;
ll par[90000];
vector<ll> dist[90000];
ll mxd = 0;

void dfs(ll x, ll p, ll d) {
    par[x] = p;
    for (auto i : G[x]) {
        if (i.first != p) {
            ord.push_back(i.second);
            dist[d].push_back(i.second);
            mxd = max(mxd, d);
            dfs(i.first, x, d + 1);
        }
    }
}

void find_pair(int N, vector<int> U, vector<int> V, int A, int B) {
    map< pair<ll, ll>, ll > mp;
    pair<ll, ll> p = {-1, -1};
    n = N;
    for (int i = 0; i < n - 1; i++) {
        G[U[i]].push_back({V[i], i});
        G[V[i]].push_back({U[i], i});
        mp[{U[i], V[i]}] = i;
        mp[{V[i], U[i]}] = i;
    }
    vector<int> w(n - 1, 1);
    ll dst = ask(w) / B;
    dfs(0, -1, 0);
    for (int i = 0; i < n - 1; i++) {
        if (par[U[i]] == V[i]) {
            swap(U[i], V[i]);
        }
    }
    ll l = 0, r = mxd;
    while (r > l) {
        ll mid = (r + l) / 2;
        w.assign(n - 1, 0);
        for (int i = 0; i <= mid; i++) {
            for (int j : dist[i]) {
                w[j] = 1;
            }
        }
        if (ask(w) == dst * B) {
            r = mid;
        }
        else {
            l = mid + 1;
        }
    }
    ll elow = l;
    w.assign(n - 1, 0);
    for (int i = 0; i <= l; i++) {
        for (int j : dist[i]) {
            w[j] = 1;
        }
    }
    l = 0;
    r = dist[elow].size() - 1;
    while (r > l) {
        ll mid = (r + l) / 2;
        w.assign(n - 1, 0);
        for (int i = 0; i <= mid; i++) {
            w[dist[elow][i]] = 1;
        }
        // cout << mid << ' ' << dst * B << ' ' << ask(w) << ' ' << (B - A) << ' ' << (elow - mid + 1) << '\n';
        if (ask(w) != dst * A) {
            r = mid;
        }
        else {
            l = mid + 1;
        }
    } 
    p.second = V[dist[elow][l]];
    w.assign(n - 1, 0);
    ll e = p.second;
    while (e != 0) {
        w[mp[{e, par[e]}]] = 1;
        e = par[e];
    }
    if (ask(w) == dst * B) {
        e = p.second;
        for (int i = 0; i < dst; i++) {
            e = par[e];
        }
        p.first = e;
        answer(p.first, p.second);
        return;
    }
    ord.clear();
    for (int i = 0; i < mxd; i++) {
        dist[i].clear();
    }
    mxd = 0;
    dfs(p.second, -1, 0);
    for (int i = 0; i < n - 1; i++) {
        if (par[U[i]] == V[i]) {
            swap(U[i], V[i]);
        }
    }
    l = 0;
    r = n - 1;
    while (r > l) {
        ll mid = (r + l) / 2;
        w.assign(n - 1, 0);
        for (int i = 0; i <= mid; i++) {
            w[ord[i]] = 1;
        }
        if (ask(w) >= dst * B) {
            r = mid;
        }
        else {
            l = mid + 1;
        }
    }
    p.first = V[ord[l]];
    // cout << p.first << ' ' << p.second << '\n';
    answer(p.first, p.second);
}

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 6 / 6
• Subtask 4: 33 / 33
• Subtask 5: 0 / 18
• Subtask 6: 0 / 31