oj.uz

Submission #802389

# Submission time Handle Problem Language Result Execution time Memory
802389 2023-08-02T12:03:39 Z boris_mihov Highway Tolls (IOI18_highway) C++17
39 / 100
 127 ms 34336 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;
    }
    
    std::fill(w.begin(), w.end(), 1);
    for (int i = 0 ; i < order.size() ; ++i)
    {
        w[order[i]] = 0;
    }

    llong res = ask(w);
    while (res != 1LL * cnt * a + 1LL * cnt2 * b);
    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

highway.cpp: In function 'int find(std::vector<std::pair<int, int> >*, int, int, int)':
highway.cpp:76:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   76 |     for (int i = 0 ; i < order.size() ; ++i)
      |                      ~~^~~~~~~~~~~~~~
In file included from /usr/include/c++/10/cassert:44,
                 from highway.cpp:5:
highway.cpp:83:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   83 |     assert(r < order.size());
      |            ~~^~~~~~~~~~~~~~

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6736 KB Output is correct
2 Correct 3 ms 6608 KB Output is correct
3 Correct 4 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 6560 KB Output is correct
7 Correct 3 ms 6608 KB Output is correct
8 Runtime error 10 ms 13304 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 6736 KB Output is correct
2 Correct 13 ms 7808 KB Output is correct
3 Correct 127 ms 17484 KB Output is correct
4 Correct 98 ms 17612 KB Output is correct
5 Correct 94 ms 17504 KB Output is correct
6 Correct 93 ms 17548 KB Output is correct
7 Correct 98 ms 17504 KB Output is correct
8 Correct 98 ms 17512 KB Output is correct
9 Runtime error 109 ms 34336 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 7632 KB Output is correct
2 Correct 22 ms 8816 KB Output is correct
3 Correct 67 ms 9744 KB Output is correct
4 Correct 72 ms 16268 KB Output is correct
5 Correct 72 ms 16252 KB Output is correct
6 Correct 74 ms 16304 KB Output is correct
7 Correct 66 ms 15948 KB Output is correct
8 Correct 85 ms 16268 KB Output is correct
9 Correct 69 ms 16128 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 6708 KB Output is correct
2 Correct 16 ms 7760 KB Output is correct
3 Correct 72 ms 15192 KB Output is correct
4 Correct 98 ms 17504 KB Output is correct
5 Correct 95 ms 17476 KB Output is correct
6 Correct 92 ms 17484 KB Output is correct
7 Correct 88 ms 17052 KB Output is correct
8 Correct 104 ms 17504 KB Output is correct
9 Correct 103 ms 17456 KB Output is correct
10 Correct 98 ms 17480 KB Output is correct
11 Correct 105 ms 16380 KB Output is correct
12 Correct 108 ms 16356 KB Output is correct
13 Correct 113 ms 16300 KB Output is correct
14 Correct 120 ms 16248 KB Output is correct
15 Correct 106 ms 17512 KB Output is correct
16 Correct 94 ms 17476 KB Output is correct
17 Correct 123 ms 16348 KB Output is correct
18 Correct 107 ms 16364 KB Output is correct
19 Correct 114 ms 17492 KB Output is correct
20 Correct 101 ms 16388 KB Output is correct
21 Correct 97 ms 18188 KB Output is correct
22 Correct 81 ms 18192 KB Output is correct
23 Correct 92 ms 17920 KB Output is correct
24 Correct 95 ms 17812 KB Output is correct
25 Correct 96 ms 16548 KB Output is correct

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 7812 KB Output is correct
2 Incorrect 13 ms 7932 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 15768 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -