oj.uz

Submission #893954

# Submission time Handle Problem Language Result Execution time Memory
893954 2023-12-27T17:43:58 Z borisAngelov Evacuation plan (IZhO18_plan) C++17
41 / 100
 4000 ms 36400 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)
    {
        if (s.find(dist[i]) == s.end())
        {
            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));
            }
        }
    }

    if (clock() / CLOCKS_PER_SEC > 1.0)
    {
        return 0;
    }

    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:244:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  244 |         for (int i = 0; i < g[node].size(); ++i)
      |                         ~~^~~~~~~~~~~~~~~~
plan.cpp:270:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  270 |         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 2 ms 7512 KB Output is correct
3 Correct 3 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 5 ms 7516 KB Output is correct
10 Correct 2 ms 7516 KB Output is correct
11 Correct 5 ms 7516 KB Output is correct
12 Correct 3 ms 7516 KB Output is correct
13 Correct 5 ms 7480 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 2 ms 7512 KB Output is correct
3 Correct 3 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 5 ms 7516 KB Output is correct
10 Correct 2 ms 7516 KB Output is correct
11 Correct 5 ms 7516 KB Output is correct
12 Correct 3 ms 7516 KB Output is correct
13 Correct 5 ms 7480 KB Output is correct
14 Correct 5 ms 7516 KB Output is correct
15 Correct 5 ms 7516 KB Output is correct
16 Correct 3281 ms 19112 KB Output is correct
17 Correct 2321 ms 36400 KB Output is correct
18 Correct 205 ms 10060 KB Output is correct
19 Correct 78 ms 29796 KB Output is correct
20 Correct 2404 ms 36372 KB Output is correct
21 Correct 293 ms 31532 KB Output is correct
22 Execution timed out 4074 ms 19832 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 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 2 ms 7516 KB Output is correct
8 Correct 2 ms 7516 KB Output is correct
9 Correct 2 ms 7328 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 126 ms 18056 KB Output is correct
2 Correct 294 ms 30576 KB Output is correct
3 Correct 281 ms 30368 KB Output is correct
4 Correct 102 ms 16368 KB Output is correct
5 Correct 274 ms 30888 KB Output is correct
6 Correct 243 ms 29744 KB Output is correct
7 Correct 256 ms 30404 KB Output is correct
8 Correct 294 ms 29856 KB Output is correct
9 Correct 250 ms 29636 KB Output is correct
10 Correct 264 ms 30464 KB Output is correct
11 Correct 266 ms 30544 KB Output is correct
12 Correct 285 ms 30724 KB Output is correct
13 Correct 303 ms 30404 KB Output is correct
14 Correct 259 ms 29776 KB Output is correct
15 Correct 265 ms 30656 KB Output is correct
16 Correct 274 ms 30288 KB Output is correct
17 Correct 246 ms 29540 KB Output is correct
18 Correct 259 ms 29784 KB Output is correct
19 Correct 83 ms 16340 KB Output is correct
20 Correct 292 ms 30404 KB Output is correct
21 Correct 223 ms 27800 KB Output is correct
22 Correct 51 ms 15428 KB Output is correct
23 Correct 129 ms 15564 KB Output is correct
24 Correct 55 ms 15412 KB Output is correct
25 Correct 50 ms 15424 KB Output is correct
26 Correct 103 ms 15072 KB Output is correct
27 Correct 92 ms 16332 KB Output is correct
28 Correct 53 ms 15176 KB Output is correct
29 Correct 97 ms 16336 KB Output is correct
30 Correct 53 ms 15428 KB Output is correct
31 Correct 99 ms 16264 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 2 ms 7512 KB Output is correct
3 Correct 3 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 5 ms 7516 KB Output is correct
10 Correct 2 ms 7516 KB Output is correct
11 Correct 5 ms 7516 KB Output is correct
12 Correct 3 ms 7516 KB Output is correct
13 Correct 5 ms 7480 KB Output is correct
14 Correct 5 ms 7516 KB Output is correct
15 Correct 5 ms 7516 KB Output is correct
16 Correct 3281 ms 19112 KB Output is correct
17 Correct 2321 ms 36400 KB Output is correct
18 Correct 205 ms 10060 KB Output is correct
19 Correct 78 ms 29796 KB Output is correct
20 Correct 2404 ms 36372 KB Output is correct
21 Correct 293 ms 31532 KB Output is correct
22 Execution timed out 4074 ms 19832 KB Time limit exceeded
23 Halted 0 ms 0 KB -