oj.uz

Submission #802372

# Submission time Handle Problem Language Result Execution time Memory
802372 2023-08-02T11:57:58 Z boris_mihov Highway Tolls (IOI18_highway) C++17
39 / 100
 175 ms 34368 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);
            }
        }
    }

    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:74:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   74 |     assert(r < order.size());
      |            ~~^~~~~~~~~~~~~~

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 6608 KB Output is correct
2 Correct 4 ms 6608 KB Output is correct
3 Correct 3 ms 6656 KB Output is correct
4 Correct 4 ms 6608 KB Output is correct
5 Correct 3 ms 6608 KB Output is correct
6 Correct 4 ms 6608 KB Output is correct
7 Correct 3 ms 6608 KB Output is correct
8 Runtime error 9 ms 13284 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 3 ms 6708 KB Output is correct
2 Correct 13 ms 7868 KB Output is correct
3 Correct 138 ms 17596 KB Output is correct
4 Correct 118 ms 17512 KB Output is correct
5 Correct 127 ms 17500 KB Output is correct
6 Correct 144 ms 17468 KB Output is correct
7 Correct 146 ms 17508 KB Output is correct
8 Correct 143 ms 17520 KB Output is correct
9 Runtime error 175 ms 34368 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 9 ms 7740 KB Output is correct
2 Correct 17 ms 8836 KB Output is correct
3 Correct 24 ms 9748 KB Output is correct
4 Correct 94 ms 16248 KB Output is correct
5 Correct 82 ms 16244 KB Output is correct
6 Correct 96 ms 16300 KB Output is correct
7 Correct 71 ms 15960 KB Output is correct
8 Correct 91 ms 16272 KB Output is correct
9 Correct 70 ms 16128 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 6736 KB Output is correct
2 Correct 13 ms 7812 KB Output is correct
3 Correct 78 ms 15164 KB Output is correct
4 Correct 95 ms 17504 KB Output is correct
5 Correct 109 ms 17496 KB Output is correct
6 Correct 101 ms 17480 KB Output is correct
7 Correct 81 ms 16932 KB Output is correct
8 Correct 115 ms 17500 KB Output is correct
9 Correct 104 ms 17460 KB Output is correct
10 Correct 104 ms 17476 KB Output is correct
11 Correct 94 ms 16388 KB Output is correct
12 Correct 133 ms 16412 KB Output is correct
13 Correct 120 ms 16300 KB Output is correct
14 Correct 105 ms 16260 KB Output is correct
15 Correct 96 ms 17520 KB Output is correct
16 Correct 95 ms 17488 KB Output is correct
17 Correct 118 ms 16428 KB Output is correct
18 Correct 118 ms 16372 KB Output is correct
19 Correct 120 ms 17548 KB Output is correct
20 Correct 86 ms 16376 KB Output is correct
21 Correct 113 ms 18184 KB Output is correct
22 Correct 97 ms 18192 KB Output is correct
23 Correct 115 ms 17920 KB Output is correct
24 Correct 90 ms 17768 KB Output is correct
25 Correct 143 ms 16536 KB Output is correct

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 7856 KB Output is correct
2 Incorrect 15 ms 7960 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 21 ms 15836 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -