oj.uz

Submission #802374

# Submission time Handle Problem Language Result Execution time Memory
802374 2023-08-02T11:58:30 Z boris_mihov Highway Tolls (IOI18_highway) C++17
39 / 100
 142 ms 34312 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 6656 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 6660 KB Output is correct
5 Correct 3 ms 6608 KB Output is correct
6 Correct 3 ms 6656 KB Output is correct
7 Correct 3 ms 6608 KB Output is correct
8 Runtime error 11 ms 13336 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 14 ms 7840 KB Output is correct
3 Correct 87 ms 17480 KB Output is correct
4 Correct 113 ms 17608 KB Output is correct
5 Correct 113 ms 17520 KB Output is correct
6 Correct 128 ms 17572 KB Output is correct
7 Correct 112 ms 17504 KB Output is correct
8 Correct 122 ms 17528 KB Output is correct
9 Runtime error 111 ms 34312 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 11 ms 7632 KB Output is correct
2 Correct 18 ms 8736 KB Output is correct
3 Correct 25 ms 9740 KB Output is correct
4 Correct 100 ms 16240 KB Output is correct
5 Correct 84 ms 16240 KB Output is correct
6 Correct 69 ms 16272 KB Output is correct
7 Correct 108 ms 15944 KB Output is correct
8 Correct 87 ms 16260 KB Output is correct
9 Correct 69 ms 16132 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 7804 KB Output is correct
3 Correct 87 ms 15176 KB Output is correct
4 Correct 99 ms 17516 KB Output is correct
5 Correct 81 ms 17488 KB Output is correct
6 Correct 118 ms 17480 KB Output is correct
7 Correct 85 ms 17008 KB Output is correct
8 Correct 86 ms 17504 KB Output is correct
9 Correct 139 ms 17556 KB Output is correct
10 Correct 107 ms 17484 KB Output is correct
11 Correct 103 ms 16380 KB Output is correct
12 Correct 122 ms 16360 KB Output is correct
13 Correct 97 ms 16304 KB Output is correct
14 Correct 127 ms 16256 KB Output is correct
15 Correct 100 ms 17524 KB Output is correct
16 Correct 109 ms 17500 KB Output is correct
17 Correct 116 ms 16336 KB Output is correct
18 Correct 142 ms 16372 KB Output is correct
19 Correct 113 ms 17612 KB Output is correct
20 Correct 116 ms 16392 KB Output is correct
21 Correct 88 ms 18188 KB Output is correct
22 Correct 96 ms 18296 KB Output is correct
23 Correct 126 ms 17944 KB Output is correct
24 Correct 117 ms 17832 KB Output is correct
25 Correct 110 ms 16536 KB Output is correct

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 7848 KB Output is correct
2 Incorrect 17 ms 7884 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 23 ms 15812 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -