oj.uz

Submission #802396

# Submission time Handle Problem Language Result Execution time Memory
802396 2023-08-02T12:06:47 Z boris_mihov Highway Tolls (IOI18_highway) C++17
39 / 100
 1500 ms 18408 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);
        assert(res >= 1LL * a * cnt + 1LL * b * cnt2);
        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 || r == order.size());
    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)
      |                      ~~^~~~~~~~~~~~~~
highway.cpp:82:55: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |     while (res != 1LL * cnt * a + 1LL * cnt2 * b || r == order.size());
      |                                                     ~~^~~~~~~~~~~~~~~
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 6636 KB Output is correct
2 Correct 4 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 4 ms 6608 KB Output is correct
7 Correct 3 ms 6608 KB Output is correct
8 Execution timed out 3048 ms 6656 KB Time limit exceeded
9 Halted 0 ms 0 KB -

Subtask #2
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 6784 KB Output is correct
2 Correct 14 ms 7864 KB Output is correct
3 Correct 110 ms 17476 KB Output is correct
4 Correct 137 ms 17604 KB Output is correct
5 Correct 105 ms 17508 KB Output is correct
6 Correct 132 ms 17488 KB Output is correct
7 Correct 123 ms 17508 KB Output is correct
8 Correct 99 ms 17520 KB Output is correct
9 Execution timed out 3031 ms 17496 KB Time limit exceeded
10 Halted 0 ms 0 KB -

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 7632 KB Output is correct
2 Correct 17 ms 8816 KB Output is correct
3 Correct 31 ms 9748 KB Output is correct
4 Correct 69 ms 16244 KB Output is correct
5 Correct 105 ms 16364 KB Output is correct
6 Correct 64 ms 16372 KB Output is correct
7 Correct 93 ms 15976 KB Output is correct
8 Correct 92 ms 16396 KB Output is correct
9 Correct 70 ms 16120 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 7844 KB Output is correct
3 Correct 68 ms 15176 KB Output is correct
4 Correct 100 ms 17504 KB Output is correct
5 Correct 114 ms 17480 KB Output is correct
6 Correct 110 ms 17500 KB Output is correct
7 Correct 92 ms 17008 KB Output is correct
8 Correct 98 ms 17492 KB Output is correct
9 Correct 117 ms 17452 KB Output is correct
10 Correct 134 ms 17540 KB Output is correct
11 Correct 140 ms 16416 KB Output is correct
12 Correct 120 ms 16364 KB Output is correct
13 Correct 103 ms 16304 KB Output is correct
14 Correct 99 ms 16264 KB Output is correct
15 Correct 95 ms 17516 KB Output is correct
16 Correct 113 ms 17488 KB Output is correct
17 Correct 106 ms 16420 KB Output is correct
18 Correct 114 ms 16368 KB Output is correct
19 Correct 91 ms 17488 KB Output is correct
20 Correct 110 ms 16384 KB Output is correct
21 Correct 111 ms 18408 KB Output is correct
22 Correct 115 ms 18184 KB Output is correct
23 Correct 110 ms 17924 KB Output is correct
24 Correct 104 ms 17776 KB Output is correct
25 Correct 131 ms 16528 KB Output is correct

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Runtime error 18 ms 15748 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #6
0 / 31.0

# Verdict Execution time Memory Grader output
1 Runtime error 22 ms 15952 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -