oj.uz

답안 #766372

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
766372 2023-06-25T15:05:59 Z boris_mihov 통행료 (IOI18_highway) C++17
51 / 100
 172 ms 262144 KB 
#include "highway.h"
#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>
#include <queue>

typedef long long llong;
const int MAXN = 90000 + 10;
const int INF  = 1e9;

int n, m;
int sz[MAXN];
int par[MAXN];
int parEdge[MAXN];
std::queue <int> q;
std::vector <int> w;
std::vector <std::pair <int,int>> g[MAXN];
std::queue <std::pair <int,int>> qDist;

void initDFS(int node, int p)
{
    sz[node] = 1;
    for (const auto &[u, idx] : g[node])
    {
        if (u == p)
        {
            continue;
        }   

        par[u] = node;
        parEdge[u] = idx;
        initDFS(u, node);
        sz[node] += sz[u];
    }

    if (node == 1)
    {
        sz[node]--;
    }
}

int markEdges(int root, int cnt)
{
    std::fill(w.begin(), w.end(), 0);
    if (cnt == 0)
    {
        return -1;
    }

    while (!q.empty())
    {
        q.pop();
    }

    q.push(root);
    int last = -1;
    if (root != 1)
    {
        w[parEdge[root]] = 1;
        last = parEdge[root];
        cnt--;
    }

    while (cnt)
    {
        int top = q.front();
        q.pop();

        for (const auto &[u, idx] : g[top])
        {
            if (cnt == 0)
            {
                break;
            }

            if (u == par[top])
            {
                continue;
            }

            w[idx] = 1;
            last = idx;
            q.push(u);
            cnt--;
        }
    }

    return last;
}

std::vector <std::pair <int,int>> getKth(int node, int k)
{
    assert(node != 1);
    w[parEdge[node]] = 1;
    std::vector <std::pair <int,int>> candidates;
    qDist.push({node, 1});

    while (!qDist.empty())
    {
        auto [top, dist] = qDist.front();
        qDist.pop();

        if (dist == k)
        {
            candidates.push_back({top, parEdge[top]});
            continue;
        }

        for (const auto &[u, idx] : g[top])
        {
            if (u == par[top])
            {
                continue;
            }

            w[idx] = 1;
            qDist.push({u, dist + 1});
        }
    }

    return candidates;
}

void find_pair(int N, std::vector <int> U, std::vector <int> V, int A, int B) 
{ 
    n = N;
    m = U.size();

    for (int i = 0 ; i < m ; ++i)
    {
        U[i]++;
        V[i]++;
        g[U[i]].push_back({V[i], i});
        g[V[i]].push_back({U[i], i});
    }

    initDFS(1, 0);
    w.resize(m, 0);
    llong dist = ask(w) / A;
    int l = 0, r = n, mid, last = -1;
    while (l < r - 1)
    {
        mid = (l + r) / 2;
        int res = markEdges(1, mid);
        if (ask(w) == dist * A) l = mid;
        else
        {
            r = mid;
            last = res;
        }
    }

    assert(last != -1);
    if (U[last] == par[V[last]])
    {
        std::swap(U[last], V[last]);
    }

    markEdges(U[last], sz[U[last]]);
    llong res = ask(w);
    llong distX = (res - dist * A) / (B - A);
    llong distY = dist - distX;

    std::fill(w.begin(), w.end(), 0);
    std::vector <std::pair <int,int>> candidates = getKth(U[last], distX);

    l = -1;
    r = candidates.size() - 1;

    while (l < r - 1)
    {
        mid = (l + r) / 2;
        for (const auto &[u, idx] : candidates)
        {
            w[idx] = 0; 
        }

        for (int i = 0 ; i <= mid ; ++i)
        {
            w[candidates[i].second] = 1;
        }
    
        res = ask(w);
        if (res == distX * B + distY * A) r = mid;
        else l = mid;
    }

    int s, t;
    s = candidates[r].first;
    if (distY == 0)
    {
        answer(s - 1, V[last] - 1);
        return;
    }

    candidates.clear();
    bool isGood = false;
    std::fill(w.begin(), w.end(), 0);
    for (const auto &[u, idx] : g[V[last]])
    {
        if (u == par[V[last]])
        {
            continue;
        }

        if (u == U[last])
        {
            isGood = true;
            continue;
        }

        if (isGood)
        {
            std::vector <std::pair <int,int>> curr = getKth(u, distY);
            for (const auto &i : curr)
            {
                candidates.push_back(i);
            }
        }
    }

    l = -1, r = candidates.size() - 1;
    while (l < r - 1)
    {
        mid = (l + r) / 2;
        for (const auto &[u, idx] : candidates)
        {
            w[idx] = 0; 
        }

        for (int i = 0 ; i <= mid ; ++i)
        {
            w[candidates[i].second] = 1;
        }
    
        res = ask(w);
        if (res == distX * A + distY * B) r = mid;
        else l = mid;
    }

    t = candidates[r].first;
    answer(s - 1, t - 1);
}

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 2384 KB Output is correct
2 Correct 1 ms 2384 KB Output is correct
3 Correct 1 ms 2384 KB Output is correct
4 Correct 1 ms 2428 KB Output is correct
5 Correct 1 ms 2384 KB Output is correct
6 Correct 1 ms 2384 KB Output is correct
7 Correct 1 ms 2384 KB Output is correct
8 Correct 1 ms 2384 KB Output is correct
9 Correct 1 ms 2384 KB Output is correct
10 Correct 1 ms 2384 KB Output is correct
11 Correct 1 ms 2384 KB Output is correct
12 Correct 1 ms 2384 KB Output is correct

Subtask #2
7.0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 2384 KB Output is correct
2 Correct 10 ms 3128 KB Output is correct
3 Correct 84 ms 8908 KB Output is correct
4 Correct 107 ms 8908 KB Output is correct
5 Correct 78 ms 8904 KB Output is correct
6 Correct 92 ms 8864 KB Output is correct
7 Correct 115 ms 8784 KB Output is correct
8 Correct 100 ms 8932 KB Output is correct
9 Correct 69 ms 8668 KB Output is correct
10 Correct 102 ms 8904 KB Output is correct
11 Correct 95 ms 9416 KB Output is correct
12 Correct 102 ms 10020 KB Output is correct
13 Correct 71 ms 9544 KB Output is correct
14 Correct 89 ms 8984 KB Output is correct

Subtask #3
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 9 ms 3664 KB Output is correct
2 Correct 20 ms 4936 KB Output is correct
3 Correct 25 ms 6164 KB Output is correct
4 Correct 79 ms 13788 KB Output is correct
5 Correct 99 ms 13684 KB Output is correct
6 Correct 90 ms 13772 KB Output is correct
7 Correct 67 ms 13696 KB Output is correct
8 Correct 93 ms 13680 KB Output is correct
9 Correct 86 ms 13688 KB Output is correct

Subtask #4
33.0 / 33.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 2384 KB Output is correct
2 Correct 11 ms 3028 KB Output is correct
3 Correct 77 ms 7288 KB Output is correct
4 Correct 129 ms 8644 KB Output is correct
5 Correct 82 ms 8644 KB Output is correct
6 Correct 76 ms 8644 KB Output is correct
7 Correct 106 ms 8660 KB Output is correct
8 Correct 130 ms 8636 KB Output is correct
9 Correct 115 ms 8836 KB Output is correct
10 Correct 88 ms 8804 KB Output is correct
11 Correct 78 ms 8884 KB Output is correct
12 Correct 75 ms 10104 KB Output is correct
13 Correct 121 ms 9652 KB Output is correct
14 Correct 121 ms 10052 KB Output is correct
15 Correct 83 ms 8668 KB Output is correct
16 Correct 102 ms 8652 KB Output is correct
17 Correct 109 ms 9792 KB Output is correct
18 Correct 78 ms 9396 KB Output is correct
19 Correct 68 ms 8660 KB Output is correct
20 Correct 96 ms 10516 KB Output is correct
21 Correct 88 ms 9792 KB Output is correct
22 Correct 111 ms 9296 KB Output is correct
23 Correct 116 ms 10048 KB Output is correct
24 Correct 106 ms 10484 KB Output is correct
25 Correct 106 ms 13068 KB Output is correct

Subtask #5
0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 172 ms 262144 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #6
0 / 31.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 161 ms 262144 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -