oj.uz

Submission #893956

# Submission time Handle Problem Language Result Execution time Memory
893956 2023-12-27T17:45:32 Z borisAngelov Evacuation plan (IZhO18_plan) C++17
41 / 100
 4000 ms 36672 KB 
#include <bits/stdc++.h>

using namespace std;

const int maxn = 100005;
const long long inf = (1LL << 61);

int n, m, k, q;

int startCities[maxn];

vector<pair<int, int>> g[maxn];

long long dist[maxn];

vector<long long> toTry;

struct Query
{
    int from;
    int to;
    int idx;

    Query()
    {

    }

    Query(int _from, int _to, int _idx)
    {
        from = _from;
        to = _to;
        idx = _idx;
    }
};

struct DSU
{
    struct Roll
    {
        int *pos;
        int val;
        int t;
    };

    int par[maxn];
    int dep[maxn];

    stack<Roll> rollback;

    void init()
    {
        while (!rollback.empty())
        {
            rollback.pop();
        }

        for (int i = 1; i <= n; ++i)
        {
            par[i] = i;
            dep[i] = 1;
        }
    }

    int root(int node)
    {
        if (node == par[node])
        {
            return node;
        }

        return root(par[node]);
    }

    void connect(int x, int y, int tim)
    {
        x = root(x);
        y = root(y);

        if (x == y)
        {
            return;
        }

        if (dep[x] < dep[y])
        {
            swap(x, y);
        }

        rollback.push({&par[y], par[y], tim});
        par[y] = x;

        if (dep[x] == dep[y])
        {
            rollback.push({&dep[x], dep[x], tim});
            ++dep[x];
        }
    }

    void rollbackSmaller(int tim)
    {
        while (!rollback.empty() && tim >= rollback.top().t)
        {
            *rollback.top().pos = rollback.top().val;
            rollback.pop();
        }
    }

    bool areConnected(int x, int y)
    {
        return root(x) == root(y);
    }
};

DSU dsu;

vector<Query> queries;
long long answers[maxn];

vector<pair<int, int>> byValue[maxn];

void parallelBinarySearch(int level, int l, int r, vector<Query>& curr)
{
    if (l > r)
    {
        return;
    }

    if (curr.empty())
    {
        return;
    }

    if (l == r)
    {
        for (int i = 0; i < curr.size(); ++i)
        {
            answers[curr[i].idx] = toTry[l];
        }

        return;
    }

    int mid = (l + r) / 2;

    for (int i = toTry.size() - 1; i >= mid + 1; --i)
    {
        for (int j = 0; j < byValue[i].size(); ++j)
        {
            dsu.connect(byValue[i][j].first, byValue[i][j].second, i);
        }
    }

    dsu.rollbackSmaller(mid);

    vector<Query> toLeft;
    vector<Query> toRight;

    for (int i = 0; i < curr.size(); ++i)
    {
        if (dsu.areConnected(curr[i].from, curr[i].to) == true)
        {
            toRight.push_back(curr[i]);
        }
        else
        {
            toLeft.push_back(curr[i]);
        }
    }

    parallelBinarySearch(level + 1, l, mid, toLeft);
    parallelBinarySearch(level + 1, mid + 1, r, toRight);
}

vector<long long> uniqueDistances()
{
    set<long long> s;
    vector<long long> res;

    for (int i = 1; i <= n; ++i)
    {
        s.insert(dist[i]);
    }

    for (auto element : s)
    {
        res.push_back(element);
    }

    return res;
}

void fastIO()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int main()
{
    fastIO();

    cin >> n >> m;

    for (int i = 1; i <= m; ++i)
    {
        int x, y, w;
        cin >> x >> y >> w;

        g[x].push_back(make_pair(y, w));
        g[y].push_back(make_pair(x, w));
    }

    cin >> k;

    for (int i = 1; i <= k; ++i)
    {
        cin >> startCities[i];
    }

    for (int i = 1; i <= n; ++i)
    {
        dist[i] = inf;
    }

    priority_queue<pair<long long, int>> pq;

    for (int i = 1; i <= k; ++i)
    {
        pq.push(make_pair(0, startCities[i]));
        dist[startCities[i]] = 0;
    }

    while (!pq.empty())
    {
        int node = pq.top().second;
        long long curr = -pq.top().first;
        pq.pop();

        for (int i = 0; i < g[node].size(); ++i)
        {
            long long path = g[node][i].second + curr;
            int to = g[node][i].first;

            if (dist[to] > path)
            {
                dist[to] = path;
                pq.push(make_pair(-path, to));
            }
        }
    }

    /*cout << "check " << endl;

    for (int i = 1; i <= n; ++i)
    {
        cout << dist[i] << ' ';
    }

    cout << endl;*/

    toTry = uniqueDistances();

    for (int i = 1; i <= n; ++i)
    {
        for (int j = 0; j < g[i].size(); ++j)
        {
            if (i < g[i][j].first)
            {
                long long d = min(dist[i], dist[g[i][j].first]);

                int l = 0;
                int r = toTry.size() - 1;

                while (l <= r)
                {
                    int mid = (l + r) / 2;

                    if (toTry[mid] >= d)
                    {
                        r = mid - 1;
                    }
                    else
                    {
                        l = mid + 1;
                    }
                }

                byValue[l].push_back(make_pair(i, g[i][j].first));
            }
        }
    }

    cin >> q;

    for (int i = 1; i <= q; ++i)
    {
        int from, to;
        cin >> from >> to;
        queries.push_back(Query(from, to, i));
    }

    dsu.init();

    parallelBinarySearch(1, 0, toTry.size() - 1, queries);

    for (int i = 1; i <= q; ++i)
    {
        cout << answers[i] << "\n";
    }

    return 0;
}

/*
9 12
1 9 4
1 2 5
2 3 7
2 4 3
4 3 6
3 6 4
8 7 10
6 7 5
5 8 1
9 5 7
5 4 12
6 8 2
2
4 7
5
1 6
5 3
4 8
5 8
1 5
*/

Compilation message

plan.cpp: In function 'void parallelBinarySearch(int, int, int, std::vector<Query>&)':
plan.cpp:136:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Query>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  136 |         for (int i = 0; i < curr.size(); ++i)
      |                         ~~^~~~~~~~~~~~~
plan.cpp:148:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  148 |         for (int j = 0; j < byValue[i].size(); ++j)
      |                         ~~^~~~~~~~~~~~~~~~~~~
plan.cpp:159:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Query>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  159 |     for (int i = 0; i < curr.size(); ++i)
      |                     ~~^~~~~~~~~~~~~
plan.cpp: In function 'int main()':
plan.cpp:241:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  241 |         for (int i = 0; i < g[node].size(); ++i)
      |                         ~~^~~~~~~~~~~~~~~~
plan.cpp:267:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  267 |         for (int j = 0; j < g[i].size(); ++j)
      |                         ~~^~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 7256 KB Output is correct
2 Correct 2 ms 7516 KB Output is correct
3 Correct 2 ms 7516 KB Output is correct
4 Correct 2 ms 7260 KB Output is correct
5 Correct 2 ms 7516 KB Output is correct
6 Correct 2 ms 7516 KB Output is correct
7 Correct 2 ms 7516 KB Output is correct
8 Correct 1 ms 7516 KB Output is correct
9 Correct 5 ms 7516 KB Output is correct
10 Correct 2 ms 7512 KB Output is correct
11 Correct 5 ms 7516 KB Output is correct
12 Correct 2 ms 7516 KB Output is correct
13 Correct 4 ms 7684 KB Output is correct
14 Correct 5 ms 7564 KB Output is correct
15 Correct 5 ms 7516 KB Output is correct

Subtask #2
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 7256 KB Output is correct
2 Correct 2 ms 7516 KB Output is correct
3 Correct 2 ms 7516 KB Output is correct
4 Correct 2 ms 7260 KB Output is correct
5 Correct 2 ms 7516 KB Output is correct
6 Correct 2 ms 7516 KB Output is correct
7 Correct 2 ms 7516 KB Output is correct
8 Correct 1 ms 7516 KB Output is correct
9 Correct 5 ms 7516 KB Output is correct
10 Correct 2 ms 7512 KB Output is correct
11 Correct 5 ms 7516 KB Output is correct
12 Correct 2 ms 7516 KB Output is correct
13 Correct 4 ms 7684 KB Output is correct
14 Correct 5 ms 7564 KB Output is correct
15 Correct 5 ms 7516 KB Output is correct
16 Correct 3307 ms 19108 KB Output is correct
17 Correct 2319 ms 36212 KB Output is correct
18 Correct 209 ms 10116 KB Output is correct
19 Correct 77 ms 29696 KB Output is correct
20 Correct 2389 ms 36672 KB Output is correct
21 Correct 306 ms 31476 KB Output is correct
22 Execution timed out 4022 ms 19764 KB Time limit exceeded
23 Halted 0 ms 0 KB -

Subtask #3
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 7512 KB Output is correct
2 Correct 2 ms 7516 KB Output is correct
3 Correct 1 ms 7516 KB Output is correct
4 Correct 1 ms 7516 KB Output is correct
5 Correct 2 ms 7516 KB Output is correct
6 Correct 2 ms 7516 KB Output is correct
7 Correct 2 ms 7516 KB Output is correct
8 Correct 2 ms 7516 KB Output is correct
9 Correct 2 ms 7516 KB Output is correct
10 Correct 2 ms 7516 KB Output is correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 114 ms 18108 KB Output is correct
2 Correct 263 ms 30548 KB Output is correct
3 Correct 264 ms 30408 KB Output is correct
4 Correct 86 ms 16340 KB Output is correct
5 Correct 279 ms 30804 KB Output is correct
6 Correct 301 ms 29520 KB Output is correct
7 Correct 269 ms 30396 KB Output is correct
8 Correct 253 ms 29880 KB Output is correct
9 Correct 276 ms 29632 KB Output is correct
10 Correct 269 ms 30664 KB Output is correct
11 Correct 335 ms 30368 KB Output is correct
12 Correct 308 ms 30632 KB Output is correct
13 Correct 285 ms 30272 KB Output is correct
14 Correct 285 ms 29964 KB Output is correct
15 Correct 305 ms 30724 KB Output is correct
16 Correct 270 ms 30404 KB Output is correct
17 Correct 270 ms 29632 KB Output is correct
18 Correct 255 ms 29832 KB Output is correct
19 Correct 77 ms 16256 KB Output is correct
20 Correct 262 ms 30296 KB Output is correct
21 Correct 215 ms 29308 KB Output is correct
22 Correct 51 ms 15232 KB Output is correct
23 Correct 120 ms 15564 KB Output is correct
24 Correct 56 ms 15408 KB Output is correct
25 Correct 61 ms 15512 KB Output is correct
26 Correct 99 ms 15112 KB Output is correct
27 Correct 87 ms 16380 KB Output is correct
28 Correct 50 ms 15176 KB Output is correct
29 Correct 107 ms 16332 KB Output is correct
30 Correct 51 ms 15200 KB Output is correct
31 Correct 89 ms 16332 KB Output is correct

Subtask #5
0 / 46.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 7256 KB Output is correct
2 Correct 2 ms 7516 KB Output is correct
3 Correct 2 ms 7516 KB Output is correct
4 Correct 2 ms 7260 KB Output is correct
5 Correct 2 ms 7516 KB Output is correct
6 Correct 2 ms 7516 KB Output is correct
7 Correct 2 ms 7516 KB Output is correct
8 Correct 1 ms 7516 KB Output is correct
9 Correct 5 ms 7516 KB Output is correct
10 Correct 2 ms 7512 KB Output is correct
11 Correct 5 ms 7516 KB Output is correct
12 Correct 2 ms 7516 KB Output is correct
13 Correct 4 ms 7684 KB Output is correct
14 Correct 5 ms 7564 KB Output is correct
15 Correct 5 ms 7516 KB Output is correct
16 Correct 3307 ms 19108 KB Output is correct
17 Correct 2319 ms 36212 KB Output is correct
18 Correct 209 ms 10116 KB Output is correct
19 Correct 77 ms 29696 KB Output is correct
20 Correct 2389 ms 36672 KB Output is correct
21 Correct 306 ms 31476 KB Output is correct
22 Execution timed out 4022 ms 19764 KB Time limit exceeded
23 Halted 0 ms 0 KB -