oj.uz

Submission #802378

# Submission time Handle Problem Language Result Execution time Memory
802378 2023-08-02T11:59:11 Z boris_mihov Highway Tolls (IOI18_highway) C++17
39 / 100
 120 ms 34380 KB 
#include "highway.h"
#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <numeric>
#include <vector>
#include <queue>

typedef long long llong;
const int MAXN = 90000 + 10;
const llong INF = 1e18;
const int INTINF = 1e9;

int n, m, a, b;
std::queue <int> q;
std::vector <std::pair <int,int>> g[MAXN];
std::vector <std::pair <int,int>> t1[MAXN];
std::vector <std::pair <int,int>> t2[MAXN];
std::vector <int> edgeU;
std::vector <int> edgeV;
int inTree[MAXN];
bool vis[MAXN];
int par[MAXN];

int find(std::vector <std::pair <int,int>> t[], int root, int cnt, int cnt2)
{
    // std::cout << "find: " << root << ' ' << cnt << '\n' << std::flush;
    if (cnt == 0)
    {
        return root;
    }

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

    std::vector <int> order;
    q.push(root);

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

        for (const auto &[u, idx] : t[top])
        {
            if (u != par[top])
            {
                order.push_back(idx);
                q.push(u);
            }
        }
    }

    while (order.empty());
    std::vector <int> w(m);
    int l = -1, r = order.size(), mid;
    while (l < r - 1)
    {
        mid = (l + r) / 2;
        std::fill(w.begin(), w.end(), 1);

        for (int i = 0 ; i <= mid ; ++i)
        {
            w[order[i]] = 0;
        }

        llong res = ask(w);
        if (res > 1LL * a * cnt + 1LL * b * cnt2) l = mid;
        else r = mid;
    }

    assert(r < order.size());
    int u = edgeU[order[r]];
    int v = edgeV[order[r]];
    if (par[v] == u)
    {
        std::swap(u, v);
    }

    return u;
}

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

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

    std::vector <int> toAsk(m, 0);
    llong res = ask(toAsk);

    int l = -1, r = m, mid;
    while (l < r - 1)
    {
        mid = (l + r) / 2;
        std::fill(toAsk.begin(), toAsk.end(), 0);
        for (int i = 0 ; i <= mid ; ++i)
        {
            toAsk[i] = 1;
        }

        llong curr = ask(toAsk);
        if (curr == res) l = mid;
        else r = mid;
    }

    assert(r < m);
    int rootOne = U[r];
    int rootTwo = V[r];
    inTree[rootOne] = 1;
    inTree[rootTwo] = 2;
    vis[rootOne] = true;
    vis[rootTwo] = true;
    q.push(rootOne);
    q.push(rootTwo);

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

        for (const auto &[u, idx] : g[top])
        {
            if (!vis[u])
            {
                par[u] = top;
                vis[u] = true;
                inTree[u] = inTree[top];
                if (inTree[top] == 1)
                {
                    t1[top].push_back({u, idx});
                    t1[u].push_back({top, idx});
                } else
                {
                    t2[top].push_back({u, idx});
                    t2[u].push_back({top, idx});
                }

                q.push(u);
            }
        }
    }       

    std::fill(toAsk.begin(), toAsk.end(), 0);
    for (int i = 0 ; i < n ; ++i)
    {
        for (const auto &[u, idx] : t1[i])
        {
            toAsk[idx] = 1;
        }
    }
    std::fill(toAsk.begin(), toAsk.end(), 0);
    for (int i = 0 ; i < n ; ++i)
    {
        for (const auto &[u, idx] : t1[i])
        {
            toAsk[idx] = 1;
        }
    }

    llong currRES = ask(toAsk);
    int cntEdges = (currRES - res) / (b - a);
    int cntEdges2 = res / a - cntEdges - 1;
    int s = find(t1, rootOne, cntEdges, cntEdges2 + 1);
    int t = find(t2, rootTwo, cntEdges2, cntEdges + 1);
    answer(s, t);
}

/*
9 12 1 10 1 3
0 1
1 2
2 6
6 3
3 4
4 0
0 5
5 6
6 7
7 0
0 8
8 6
*/

Compilation message

In file included from /usr/include/c++/10/cassert:44,
                 from highway.cpp:5:
highway.cpp: In function 'int find(std::vector<std::pair<int, int> >*, int, int, int)':
highway.cpp:75:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |     assert(r < order.size());
      |            ~~^~~~~~~~~~~~~~

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6608 KB Output is correct
2 Correct 3 ms 6608 KB Output is correct
3 Correct 3 ms 6608 KB Output is correct
4 Correct 3 ms 6608 KB Output is correct
5 Correct 3 ms 6608 KB Output is correct
6 Correct 3 ms 6608 KB Output is correct
7 Correct 3 ms 6608 KB Output is correct
8 Runtime error 8 ms 13248 KB Execution killed with signal 6
9 Halted 0 ms 0 KB -

Subtask #2
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 6736 KB Output is correct
2 Correct 13 ms 7884 KB Output is correct
3 Correct 106 ms 17476 KB Output is correct
4 Correct 102 ms 17508 KB Output is correct
5 Correct 97 ms 17500 KB Output is correct
6 Correct 102 ms 17496 KB Output is correct
7 Correct 106 ms 17512 KB Output is correct
8 Correct 100 ms 17516 KB Output is correct
9 Runtime error 106 ms 34380 KB Execution killed with signal 6
10 Halted 0 ms 0 KB -

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 7624 KB Output is correct
2 Correct 19 ms 8784 KB Output is correct
3 Correct 27 ms 9748 KB Output is correct
4 Correct 77 ms 16240 KB Output is correct
5 Correct 68 ms 16256 KB Output is correct
6 Correct 70 ms 16308 KB Output is correct
7 Correct 69 ms 15948 KB Output is correct
8 Correct 82 ms 16256 KB Output is correct
9 Correct 67 ms 16376 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6704 KB Output is correct
2 Correct 12 ms 7820 KB Output is correct
3 Correct 111 ms 15164 KB Output is correct
4 Correct 97 ms 17520 KB Output is correct
5 Correct 109 ms 17480 KB Output is correct
6 Correct 85 ms 17488 KB Output is correct
7 Correct 90 ms 16996 KB Output is correct
8 Correct 87 ms 17492 KB Output is correct
9 Correct 120 ms 17460 KB Output is correct
10 Correct 105 ms 17600 KB Output is correct
11 Correct 101 ms 16388 KB Output is correct
12 Correct 109 ms 16400 KB Output is correct
13 Correct 104 ms 16300 KB Output is correct
14 Correct 117 ms 16260 KB Output is correct
15 Correct 106 ms 17512 KB Output is correct
16 Correct 92 ms 17484 KB Output is correct
17 Correct 113 ms 16344 KB Output is correct
18 Correct 110 ms 16372 KB Output is correct
19 Correct 117 ms 17532 KB Output is correct
20 Correct 103 ms 16380 KB Output is correct
21 Correct 84 ms 18192 KB Output is correct
22 Correct 103 ms 18192 KB Output is correct
23 Correct 118 ms 17924 KB Output is correct
24 Correct 103 ms 17784 KB Output is correct
25 Correct 113 ms 16528 KB Output is correct

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 7860 KB Output is correct
2 Incorrect 13 ms 7888 KB Output is incorrect: {s, t} is wrong.
3 Halted 0 ms 0 KB -

Subtask #6
0 / 31.0

# Verdict Execution time Memory Grader output
1 Runtime error 20 ms 15824 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -