oj.uz

Submission #893991

# Submission time Handle Problem Language Result Execution time Memory
893991 2023-12-27T18:23:59 Z borisAngelov Evacuation plan (IZhO18_plan) C++17
41 / 100
 4000 ms 34384 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]);
        }
    }

    curr.clear();

    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 - 1));
    }

    dsu.init();

    vector<int> starting;

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

    if (clock() / CLOCKS_PER_SEC > 0.1)
    {
        return 1;
    }

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

    for (int i = 0; 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:243:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  243 |         for (int i = 0; i < g[node].size(); ++i)
      |                         ~~^~~~~~~~~~~~~~~~
plan.cpp:260:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  260 |         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 7256 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 6 ms 7512 KB Output is correct
10 Correct 2 ms 7512 KB Output is correct
11 Correct 5 ms 7772 KB Output is correct
12 Correct 2 ms 7516 KB Output is correct
13 Correct 6 ms 7512 KB Output is correct
14 Correct 5 ms 7516 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 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 7256 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 6 ms 7512 KB Output is correct
10 Correct 2 ms 7512 KB Output is correct
11 Correct 5 ms 7772 KB Output is correct
12 Correct 2 ms 7516 KB Output is correct
13 Correct 6 ms 7512 KB Output is correct
14 Correct 5 ms 7516 KB Output is correct
15 Correct 5 ms 7516 KB Output is correct
16 Correct 3452 ms 17156 KB Output is correct
17 Correct 2558 ms 34048 KB Output is correct
18 Correct 204 ms 9928 KB Output is correct
19 Correct 72 ms 22080 KB Output is correct
20 Correct 2478 ms 34384 KB Output is correct
21 Correct 296 ms 23848 KB Output is correct
22 Execution timed out 4025 ms 18552 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 7516 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 1 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 7260 KB Output is correct
9 Correct 2 ms 7512 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 119 ms 18044 KB Output is correct
2 Correct 305 ms 30576 KB Output is correct
3 Correct 312 ms 30276 KB Output is correct
4 Correct 97 ms 16460 KB Output is correct
5 Correct 304 ms 30820 KB Output is correct
6 Correct 334 ms 29636 KB Output is correct
7 Correct 283 ms 30628 KB Output is correct
8 Correct 269 ms 29708 KB Output is correct
9 Correct 275 ms 29652 KB Output is correct
10 Correct 329 ms 30540 KB Output is correct
11 Correct 297 ms 30380 KB Output is correct
12 Correct 277 ms 30656 KB Output is correct
13 Correct 334 ms 30272 KB Output is correct
14 Correct 331 ms 29816 KB Output is correct
15 Correct 282 ms 32016 KB Output is correct
16 Correct 283 ms 30452 KB Output is correct
17 Correct 280 ms 29632 KB Output is correct
18 Correct 281 ms 29832 KB Output is correct
19 Correct 85 ms 16340 KB Output is correct
20 Correct 281 ms 30272 KB Output is correct
21 Correct 253 ms 28092 KB Output is correct
22 Correct 48 ms 15424 KB Output is correct
23 Correct 133 ms 15356 KB Output is correct
24 Correct 76 ms 15408 KB Output is correct
25 Correct 49 ms 15268 KB Output is correct
26 Correct 106 ms 15260 KB Output is correct
27 Correct 101 ms 16336 KB Output is correct
28 Correct 49 ms 15352 KB Output is correct
29 Correct 85 ms 16380 KB Output is correct
30 Correct 47 ms 15424 KB Output is correct
31 Correct 89 ms 16492 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 7256 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 6 ms 7512 KB Output is correct
10 Correct 2 ms 7512 KB Output is correct
11 Correct 5 ms 7772 KB Output is correct
12 Correct 2 ms 7516 KB Output is correct
13 Correct 6 ms 7512 KB Output is correct
14 Correct 5 ms 7516 KB Output is correct
15 Correct 5 ms 7516 KB Output is correct
16 Correct 3452 ms 17156 KB Output is correct
17 Correct 2558 ms 34048 KB Output is correct
18 Correct 204 ms 9928 KB Output is correct
19 Correct 72 ms 22080 KB Output is correct
20 Correct 2478 ms 34384 KB Output is correct
21 Correct 296 ms 23848 KB Output is correct
22 Execution timed out 4025 ms 18552 KB Time limit exceeded
23 Halted 0 ms 0 KB -