oj.uz

Submission #893982

# Submission time Handle Problem Language Result Execution time Memory
893982 2023-12-27T18:18:18 Z borisAngelov Evacuation plan (IZhO18_plan) C++17
41 / 100
 4000 ms 34388 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();
        }
    }

    inline 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 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 + 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<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(l, mid, toLeft);
    parallelBinarySearch(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));
            }
        }
    }

    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(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, 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:258:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  258 |         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 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 7512 KB Output is correct
5 Correct 2 ms 7512 KB Output is correct
6 Correct 3 ms 7512 KB Output is correct
7 Correct 2 ms 7516 KB Output is correct
8 Correct 2 ms 7516 KB Output is correct
9 Correct 5 ms 7516 KB Output is correct
10 Correct 2 ms 7516 KB Output is correct
11 Correct 5 ms 7656 KB Output is correct
12 Correct 2 ms 7516 KB Output is correct
13 Correct 4 ms 7516 KB Output is correct
14 Correct 5 ms 7656 KB Output is correct
15 Correct 5 ms 7452 KB Output is correct

Subtask #2
0 / 13.0

# 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 2 ms 7516 KB Output is correct
4 Correct 2 ms 7512 KB Output is correct
5 Correct 2 ms 7512 KB Output is correct
6 Correct 3 ms 7512 KB Output is correct
7 Correct 2 ms 7516 KB Output is correct
8 Correct 2 ms 7516 KB Output is correct
9 Correct 5 ms 7516 KB Output is correct
10 Correct 2 ms 7516 KB Output is correct
11 Correct 5 ms 7656 KB Output is correct
12 Correct 2 ms 7516 KB Output is correct
13 Correct 4 ms 7516 KB Output is correct
14 Correct 5 ms 7656 KB Output is correct
15 Correct 5 ms 7452 KB Output is correct
16 Correct 3228 ms 17096 KB Output is correct
17 Correct 2363 ms 34092 KB Output is correct
18 Correct 204 ms 9964 KB Output is correct
19 Correct 81 ms 22084 KB Output is correct
20 Correct 2479 ms 34388 KB Output is correct
21 Correct 300 ms 23744 KB Output is correct
22 Execution timed out 4043 ms 18736 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 7260 KB Output is correct
4 Correct 2 ms 7516 KB Output is correct
5 Correct 2 ms 7512 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 1 ms 7516 KB Output is correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 148 ms 18124 KB Output is correct
2 Correct 288 ms 30532 KB Output is correct
3 Correct 304 ms 30412 KB Output is correct
4 Correct 99 ms 16336 KB Output is correct
5 Correct 367 ms 30804 KB Output is correct
6 Correct 321 ms 29620 KB Output is correct
7 Correct 365 ms 30588 KB Output is correct
8 Correct 331 ms 29776 KB Output is correct
9 Correct 346 ms 29760 KB Output is correct
10 Correct 388 ms 30536 KB Output is correct
11 Correct 338 ms 30404 KB Output is correct
12 Correct 330 ms 30832 KB Output is correct
13 Correct 328 ms 30268 KB Output is correct
14 Correct 365 ms 29908 KB Output is correct
15 Correct 349 ms 31148 KB Output is correct
16 Correct 403 ms 30300 KB Output is correct
17 Correct 384 ms 29808 KB Output is correct
18 Correct 328 ms 29784 KB Output is correct
19 Correct 88 ms 16348 KB Output is correct
20 Correct 274 ms 30284 KB Output is correct
21 Correct 279 ms 29068 KB Output is correct
22 Correct 50 ms 15428 KB Output is correct
23 Correct 119 ms 15528 KB Output is correct
24 Correct 49 ms 15172 KB Output is correct
25 Correct 53 ms 15432 KB Output is correct
26 Correct 100 ms 15056 KB Output is correct
27 Correct 88 ms 16332 KB Output is correct
28 Correct 50 ms 15176 KB Output is correct
29 Correct 104 ms 16332 KB Output is correct
30 Correct 59 ms 15424 KB Output is correct
31 Correct 87 ms 16336 KB Output is correct

Subtask #5
0 / 46.0

# 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 2 ms 7516 KB Output is correct
4 Correct 2 ms 7512 KB Output is correct
5 Correct 2 ms 7512 KB Output is correct
6 Correct 3 ms 7512 KB Output is correct
7 Correct 2 ms 7516 KB Output is correct
8 Correct 2 ms 7516 KB Output is correct
9 Correct 5 ms 7516 KB Output is correct
10 Correct 2 ms 7516 KB Output is correct
11 Correct 5 ms 7656 KB Output is correct
12 Correct 2 ms 7516 KB Output is correct
13 Correct 4 ms 7516 KB Output is correct
14 Correct 5 ms 7656 KB Output is correct
15 Correct 5 ms 7452 KB Output is correct
16 Correct 3228 ms 17096 KB Output is correct
17 Correct 2363 ms 34092 KB Output is correct
18 Correct 204 ms 9964 KB Output is correct
19 Correct 81 ms 22084 KB Output is correct
20 Correct 2479 ms 34388 KB Output is correct
21 Correct 300 ms 23744 KB Output is correct
22 Execution timed out 4043 ms 18736 KB Time limit exceeded
23 Halted 0 ms 0 KB -