제출 #1173497

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1173497		anmattroi	통행료 (IOI18_highway)	C++17	100 / 100	115 ms	11312 KiB

highway

#include "highway.h"
#include <bits/stdc++.h>
#define fi first
#define se second
using namespace std;
using ii = pair<int, int>;

void find_pair(int N, vector<int> U, vector<int> V, int A, int B) {
    int M = U.size();
    vector<vector<ii> > adj(N);

    for (int i = 0; i < M; i++) {
        adj[U[i]].emplace_back(V[i], i);
        adj[V[i]].emplace_back(U[i], i);
    }

    int64_t all_b = ask(vector<int>(M, 1)),
            all_a = all_b / B * A;

    int lo = -1, hi = M-1;

    while (hi - lo > 1) {
        int mid = (lo + hi) >> 1;
        vector<int> orz(M, 0);
        for (int i = 0; i <= mid; i++) orz[i] = 1;
        if (ask(orz) != all_a) hi = mid;
        else lo = mid;
    }
    int X = U[hi], Y = V[hi], S, T;

    vector<int> depthX(N, INT_MAX), depthY(N, INT_MAX);
    if (1) {
        queue<int> q;
        q.push(X); depthX[X] = 0;
        while (!q.empty()) {
            int u = q.front(); q.pop();
            for (auto [v, idx] : adj[u])
            if (depthX[v] == INT_MAX) {
                depthX[v] = depthX[u] + 1;
                q.push(v);
            }
        }
    }
    if (1) {
        queue<int> q;
        q.push(Y); depthY[Y] = 0;
        while (!q.empty()) {
            int u = q.front(); q.pop();
            for (auto [v, idx] : adj[u])
            if (depthY[v] == INT_MAX) {
                depthY[v] = depthY[u] + 1;
                q.push(v);
            }
        }
    }
    vector<int> based(M, 0);

    vector<int> lisX, lisY;

    for (int i = 0; i < N; i++)
    if (depthX[i] != depthY[i]) {
        if (depthX[i] < depthY[i]) lisX.emplace_back(i);
        else lisY.emplace_back(i);
    }
    for (int i = 0; i < M; i++)
        if ((depthX[U[i]] < depthY[U[i]] and depthX[V[i]] > depthY[V[i]]) or
            (depthX[U[i]] > depthY[U[i]] and depthX[V[i]] < depthY[V[i]])) based[i] = 1;

    based[hi] = 0;

    for (int i = 0; i < N; i++) if (depthX[i] == depthY[i]) for (auto [v, idx] : adj[i]) based[idx] = 1;

    sort(lisX.begin(), lisX.end(), [&](int x, int y) {return depthX[x] > depthX[y];});
    sort(lisY.begin(), lisY.end(), [&](int x, int y) {return depthY[x] > depthY[y];});
//    cerr << X << ' ' << Y << "\n";
    if (1) {
        int lo = -1, hi = lisX.size()-1;
        while (hi - lo > 1) {
            int mid = (lo + hi) >> 1;
            vector<int> orz = based;
            for (int i = 0; i <= mid; i++) for (auto [v, idx] : adj[lisX[i]]) orz[idx] = 1;
//            cerr << "-----------\n";
//            cerr << lo << ' ' << hi << ' ' << mid << "\n";
//            for (int i = 0; i < M; i++) cerr << orz[i] << ' ';
//            cerr << "\n" << ask(orz) << "\n";
//            cerr << "---------------\n";

            if (ask(orz) != all_a) hi = mid;
            else lo = mid;
        }
        S = lisX[hi];
    }
    if (1) {
        int lo = -1, hi = lisY.size()-1;
        while (hi - lo > 1) {
            int mid = (lo + hi) >> 1;
            vector<int> orz = based;
            for (int i = 0; i <= mid; i++) for (auto [v, idx] : adj[lisY[i]]) orz[idx] = 1;
//            cerr << "-----------\n";
//            cerr << lo << ' ' << hi << ' ' << mid << "\n";
//            for (int i = 0; i < M; i++) cerr << orz[i] << ' ';
//            cerr << "\n" << ask(orz) << "\n";
//            cerr << "---------------\n";

            if (ask(orz) != all_a) hi = mid;
            else lo = mid;
        }
        T = lisY[hi];
    }
//    cerr << X << ' ' << Y << ' ' << S << ' ' << T << "\n";
//    for (int i : lisX) cerr << i << ' '; cerr << "\n";
//    for (int i : lisY) cerr << i << ' '; cerr << "\n";

    answer(S, T);
}

/*
5 6 1 2 4 2
1 0
2 0
3 1
4 1
3 0
3 4
*/

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