oj.uz

Submission #893986

# Submission time Handle Problem Language Result Execution time Memory
893986 2023-12-27T18:20:43 Z borisAngelov Evacuation plan (IZhO18_plan) C++17
41 / 100
 4000 ms 34280 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 - 1));
    }

    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 = 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: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 2 ms 7256 KB Output is correct
2 Correct 3 ms 7516 KB Output is correct
3 Correct 2 ms 7516 KB Output is correct
4 Correct 2 ms 7516 KB Output is correct
5 Correct 3 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 7524 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 7512 KB Output is correct
12 Correct 2 ms 7768 KB Output is correct
13 Correct 4 ms 7516 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 7256 KB Output is correct
2 Correct 3 ms 7516 KB Output is correct
3 Correct 2 ms 7516 KB Output is correct
4 Correct 2 ms 7516 KB Output is correct
5 Correct 3 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 7524 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 7512 KB Output is correct
12 Correct 2 ms 7768 KB Output is correct
13 Correct 4 ms 7516 KB Output is correct
14 Correct 5 ms 7516 KB Output is correct
15 Correct 5 ms 7516 KB Output is correct
16 Correct 3202 ms 17344 KB Output is correct
17 Correct 2333 ms 34044 KB Output is correct
18 Correct 200 ms 9924 KB Output is correct
19 Correct 72 ms 22076 KB Output is correct
20 Correct 2460 ms 34280 KB Output is correct
21 Correct 351 ms 23748 KB Output is correct
22 Execution timed out 4029 ms 18548 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 7256 KB Output is correct
2 Correct 2 ms 7256 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 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 2 ms 7516 KB Output is correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 139 ms 18028 KB Output is correct
2 Correct 297 ms 30404 KB Output is correct
3 Correct 287 ms 30296 KB Output is correct
4 Correct 109 ms 16452 KB Output is correct
5 Correct 290 ms 30912 KB Output is correct
6 Correct 302 ms 29700 KB Output is correct
7 Correct 278 ms 30500 KB Output is correct
8 Correct 281 ms 29800 KB Output is correct
9 Correct 300 ms 29756 KB Output is correct
10 Correct 289 ms 30660 KB Output is correct
11 Correct 310 ms 30568 KB Output is correct
12 Correct 268 ms 30748 KB Output is correct
13 Correct 284 ms 30320 KB Output is correct
14 Correct 270 ms 29812 KB Output is correct
15 Correct 265 ms 30908 KB Output is correct
16 Correct 321 ms 30272 KB Output is correct
17 Correct 255 ms 29748 KB Output is correct
18 Correct 275 ms 29896 KB Output is correct
19 Correct 79 ms 16340 KB Output is correct
20 Correct 278 ms 30404 KB Output is correct
21 Correct 242 ms 27724 KB Output is correct
22 Correct 50 ms 15424 KB Output is correct
23 Correct 113 ms 15376 KB Output is correct
24 Correct 50 ms 15176 KB Output is correct
25 Correct 50 ms 15432 KB Output is correct
26 Correct 100 ms 15112 KB Output is correct
27 Correct 89 ms 16336 KB Output is correct
28 Correct 50 ms 15376 KB Output is correct
29 Correct 92 ms 16336 KB Output is correct
30 Correct 49 ms 15324 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 2 ms 7256 KB Output is correct
2 Correct 3 ms 7516 KB Output is correct
3 Correct 2 ms 7516 KB Output is correct
4 Correct 2 ms 7516 KB Output is correct
5 Correct 3 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 7524 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 7512 KB Output is correct
12 Correct 2 ms 7768 KB Output is correct
13 Correct 4 ms 7516 KB Output is correct
14 Correct 5 ms 7516 KB Output is correct
15 Correct 5 ms 7516 KB Output is correct
16 Correct 3202 ms 17344 KB Output is correct
17 Correct 2333 ms 34044 KB Output is correct
18 Correct 200 ms 9924 KB Output is correct
19 Correct 72 ms 22076 KB Output is correct
20 Correct 2460 ms 34280 KB Output is correct
21 Correct 351 ms 23748 KB Output is correct
22 Execution timed out 4029 ms 18548 KB Time limit exceeded
23 Halted 0 ms 0 KB -