oj.uz

Submission #802376

# Submission time Handle Problem Language Result Execution time Memory
802376 2023-08-02T11:58:41 Z boris_mihov Highway Tolls (IOI18_highway) C++17
39 / 100
 141 ms 34388 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);
            }
        }
    }

    assert(order.size());
    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 4 ms 6608 KB Output is correct
3 Correct 4 ms 6608 KB Output is correct
4 Correct 4 ms 6552 KB Output is correct
5 Correct 5 ms 6608 KB Output is correct
6 Correct 4 ms 6708 KB Output is correct
7 Correct 4 ms 6656 KB Output is correct
8 Runtime error 10 ms 13264 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 5 ms 6680 KB Output is correct
2 Correct 14 ms 7880 KB Output is correct
3 Correct 109 ms 17488 KB Output is correct
4 Correct 115 ms 17504 KB Output is correct
5 Correct 120 ms 17580 KB Output is correct
6 Correct 106 ms 17488 KB Output is correct
7 Correct 124 ms 17516 KB Output is correct
8 Correct 122 ms 17516 KB Output is correct
9 Runtime error 141 ms 34388 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 13 ms 7616 KB Output is correct
2 Correct 19 ms 8816 KB Output is correct
3 Correct 24 ms 9748 KB Output is correct
4 Correct 67 ms 16244 KB Output is correct
5 Correct 78 ms 16244 KB Output is correct
6 Correct 77 ms 16304 KB Output is correct
7 Correct 77 ms 16012 KB Output is correct
8 Correct 72 ms 16376 KB Output is correct
9 Correct 78 ms 16124 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 7856 KB Output is correct
3 Correct 59 ms 15156 KB Output is correct
4 Correct 106 ms 17616 KB Output is correct
5 Correct 88 ms 17600 KB Output is correct
6 Correct 88 ms 17472 KB Output is correct
7 Correct 81 ms 16992 KB Output is correct
8 Correct 97 ms 17500 KB Output is correct
9 Correct 104 ms 17460 KB Output is correct
10 Correct 105 ms 17480 KB Output is correct
11 Correct 112 ms 16372 KB Output is correct
12 Correct 137 ms 16348 KB Output is correct
13 Correct 108 ms 16304 KB Output is correct
14 Correct 130 ms 16264 KB Output is correct
15 Correct 130 ms 17512 KB Output is correct
16 Correct 110 ms 17496 KB Output is correct
17 Correct 100 ms 16360 KB Output is correct
18 Correct 98 ms 16364 KB Output is correct
19 Correct 118 ms 17504 KB Output is correct
20 Correct 97 ms 16376 KB Output is correct
21 Correct 83 ms 18196 KB Output is correct
22 Correct 89 ms 18436 KB Output is correct
23 Correct 95 ms 17928 KB Output is correct
24 Correct 112 ms 17780 KB Output is correct
25 Correct 109 ms 16536 KB Output is correct

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 7872 KB Output is correct
2 Incorrect 12 ms 7896 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 18 ms 15848 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -