oj.uz

Submission #893969

# Submission time Handle Problem Language Result Execution time Memory
893969 2023-12-27T17:59:57 Z borisAngelov Evacuation plan (IZhO18_plan) C++17
41 / 100
 4000 ms 34292 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<int>& curr)
{
    if (l > r)
    {
        return;
    }

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

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

        return;
    }

    int mid = (l + r) / 2;

    for (int i = toTry.size() - 1; i >= mid; --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<int> toLeft;
    vector<int> toRight;

    for (int i = 0; i < curr.size(); ++i)
    {
        if (dsu.areConnected(queries[curr[i]].from, queries[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();

    vector<int> starting;

    for (int i = 0; i < q; ++i)
    {
        starting.push_back(i);
    }

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

    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<int>&)':
plan.cpp:136:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::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<int>::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 2 ms 7260 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 7472 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 7512 KB Output is correct
8 Correct 2 ms 7512 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 7512 KB Output is correct
14 Correct 6 ms 7512 KB Output is correct
15 Correct 5 ms 7512 KB Output is correct

Subtask #2
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 7260 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 7472 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 7512 KB Output is correct
8 Correct 2 ms 7512 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 7512 KB Output is correct
14 Correct 6 ms 7512 KB Output is correct
15 Correct 5 ms 7512 KB Output is correct
16 Correct 3179 ms 17220 KB Output is correct
17 Correct 2256 ms 34096 KB Output is correct
18 Correct 202 ms 9948 KB Output is correct
19 Correct 73 ms 22084 KB Output is correct
20 Correct 2368 ms 34292 KB Output is correct
21 Correct 301 ms 24260 KB Output is correct
22 Execution timed out 4027 ms 18632 KB Time limit exceeded
23 Halted 0 ms 0 KB -

Subtask #3
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 7260 KB Output is correct
2 Correct 2 ms 7516 KB Output is correct
3 Correct 1 ms 7516 KB Output is correct
4 Correct 2 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 1 ms 7516 KB Output is correct
8 Correct 2 ms 7260 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 117 ms 18164 KB Output is correct
2 Correct 270 ms 30408 KB Output is correct
3 Correct 282 ms 30408 KB Output is correct
4 Correct 91 ms 16336 KB Output is correct
5 Correct 282 ms 30912 KB Output is correct
6 Correct 280 ms 29816 KB Output is correct
7 Correct 257 ms 30568 KB Output is correct
8 Correct 269 ms 29632 KB Output is correct
9 Correct 244 ms 29576 KB Output is correct
10 Correct 277 ms 30528 KB Output is correct
11 Correct 275 ms 30420 KB Output is correct
12 Correct 262 ms 30840 KB Output is correct
13 Correct 270 ms 30376 KB Output is correct
14 Correct 272 ms 29956 KB Output is correct
15 Correct 262 ms 31424 KB Output is correct
16 Correct 263 ms 30304 KB Output is correct
17 Correct 248 ms 29428 KB Output is correct
18 Correct 252 ms 29804 KB Output is correct
19 Correct 77 ms 16272 KB Output is correct
20 Correct 289 ms 30556 KB Output is correct
21 Correct 211 ms 29440 KB Output is correct
22 Correct 50 ms 15188 KB Output is correct
23 Correct 120 ms 15736 KB Output is correct
24 Correct 49 ms 15440 KB Output is correct
25 Correct 49 ms 15428 KB Output is correct
26 Correct 99 ms 15048 KB Output is correct
27 Correct 88 ms 16336 KB Output is correct
28 Correct 51 ms 15408 KB Output is correct
29 Correct 94 ms 16592 KB Output is correct
30 Correct 49 ms 15432 KB Output is correct
31 Correct 86 ms 16336 KB Output is correct

Subtask #5
0 / 46.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 7260 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 7472 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 7512 KB Output is correct
8 Correct 2 ms 7512 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 7512 KB Output is correct
14 Correct 6 ms 7512 KB Output is correct
15 Correct 5 ms 7512 KB Output is correct
16 Correct 3179 ms 17220 KB Output is correct
17 Correct 2256 ms 34096 KB Output is correct
18 Correct 202 ms 9948 KB Output is correct
19 Correct 73 ms 22084 KB Output is correct
20 Correct 2368 ms 34292 KB Output is correct
21 Correct 301 ms 24260 KB Output is correct
22 Execution timed out 4027 ms 18632 KB Time limit exceeded
23 Halted 0 ms 0 KB -