oj.uz

Submission #893896

# Submission time Handle Problem Language Result Execution time Memory
893896 2023-12-27T16:40:21 Z borisAngelov Evacuation plan (IZhO18_plan) C++17
41 / 100
 4000 ms 30760 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];

struct DSU
{
    int par[maxn];
    int dep[maxn];

    void init()
    {
        for (int i = 1; i <= n; ++i)
        {
            par[i] = i;
            dep[i] = 1;
        }
    }

    int root(int node)
    {
        if (node == par[node])
        {
            return node;
        }

        return par[node] = root(par[node]);
    }

    void connect(int x, int y)
    {
        x = root(x);
        y = root(y);

        if (x == y)
        {
            return;
        }

        if (dep[x] >= dep[y])
        {
            par[y] = x;

            if (dep[x] == dep[y])
            {
                ++dep[x];
            }
        }
        else
        {
            par[x] = y;
        }
    }

    bool areConnected(int x, int y)
    {
        return root(x) == root(y);
    }
};

DSU dsu;

vector<long long> toTry;

struct Edge
{
    int from;
    int to;
    long long w;

    Edge()
    {

    }

    Edge(int _from, int _to, long long _w)
    {
        from = _from;
        to = _to;
        w = _w;
    }

    bool operator < (const Edge& other) const
    {
        return w < other.w;
    }
};

vector<Edge> edges;

bool check(int from, int to, long long minW)
{
    //cout << "checking for " << minW << endl;
    dsu.init();

    int l = 0;
    int r = m - 1;

    while (l <= r)
    {
        int mid = (l + r) / 2;

        if (edges[mid].w >= minW)
        {
            r = mid - 1;
        }
        else
        {
            l = mid + 1;
        }
    }

    for (int i = l; i < m; ++i)
    {
        //cout << "add edge " << edges[i].from << ' ' << edges[i].to << ' ' << edges[i].w << endl;
        dsu.connect(edges[i].from, edges[i].to);
    }

    return dsu.areConnected(from, to);
}

long long solve(int from, int to)
{
    //cout << "query " << from << " " << to << endl;

    int l = 0;
    int r = toTry.size() - 1;

    while (l <= r)
    {
        int mid = (l + r) / 2;

        if (check(from, to, toTry[mid]) == true)
        {
            l = mid + 1;
        }
        else
        {
            r = mid - 1;
        }
    }

    return toTry[r];
}

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)
            {
                edges.push_back(Edge(i, g[i][j].first, min(dist[i], dist[g[i][j].first])));
            }
        }
    }

    sort(edges.begin(), edges.end());

    cin >> q;

    for (int i = 1; i <= q; ++i)
    {
        int from, to;
        cin >> from >> to;
        cout << solve(from, to) << "\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 'int main()':
plan.cpp:225:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  225 |         for (int i = 0; i < g[node].size(); ++i)
      |                         ~~^~~~~~~~~~~~~~~~
plan.cpp:251:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  251 |         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 4444 KB Output is correct
2 Correct 10 ms 4696 KB Output is correct
3 Correct 10 ms 4444 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 10 ms 4684 KB Output is correct
6 Correct 9 ms 4444 KB Output is correct
7 Correct 1 ms 4444 KB Output is correct
8 Correct 1 ms 4444 KB Output is correct
9 Correct 23 ms 4696 KB Output is correct
10 Correct 11 ms 4664 KB Output is correct
11 Correct 22 ms 4444 KB Output is correct
12 Correct 10 ms 4696 KB Output is correct
13 Correct 23 ms 4444 KB Output is correct
14 Correct 22 ms 4444 KB Output is correct
15 Correct 23 ms 4692 KB Output is correct

Subtask #2
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4444 KB Output is correct
2 Correct 10 ms 4696 KB Output is correct
3 Correct 10 ms 4444 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 10 ms 4684 KB Output is correct
6 Correct 9 ms 4444 KB Output is correct
7 Correct 1 ms 4444 KB Output is correct
8 Correct 1 ms 4444 KB Output is correct
9 Correct 23 ms 4696 KB Output is correct
10 Correct 11 ms 4664 KB Output is correct
11 Correct 22 ms 4444 KB Output is correct
12 Correct 10 ms 4696 KB Output is correct
13 Correct 23 ms 4444 KB Output is correct
14 Correct 22 ms 4444 KB Output is correct
15 Correct 23 ms 4692 KB Output is correct
16 Execution timed out 4064 ms 11108 KB Time limit exceeded
17 Halted 0 ms 0 KB -

Subtask #3
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4440 KB Output is correct
2 Correct 1 ms 4444 KB Output is correct
3 Correct 1 ms 4444 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 1 ms 4444 KB Output is correct
6 Correct 1 ms 4440 KB Output is correct
7 Correct 1 ms 4444 KB Output is correct
8 Correct 1 ms 4444 KB Output is correct
9 Correct 1 ms 4444 KB Output is correct
10 Correct 1 ms 4444 KB Output is correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 112 ms 17572 KB Output is correct
2 Correct 295 ms 29348 KB Output is correct
3 Correct 253 ms 29548 KB Output is correct
4 Correct 79 ms 14796 KB Output is correct
5 Correct 277 ms 29556 KB Output is correct
6 Correct 246 ms 29308 KB Output is correct
7 Correct 274 ms 30760 KB Output is correct
8 Correct 234 ms 29736 KB Output is correct
9 Correct 261 ms 28996 KB Output is correct
10 Correct 258 ms 28948 KB Output is correct
11 Correct 265 ms 30032 KB Output is correct
12 Correct 260 ms 28856 KB Output is correct
13 Correct 264 ms 29260 KB Output is correct
14 Correct 248 ms 29516 KB Output is correct
15 Correct 329 ms 30020 KB Output is correct
16 Correct 254 ms 30724 KB Output is correct
17 Correct 262 ms 30484 KB Output is correct
18 Correct 262 ms 30536 KB Output is correct
19 Correct 68 ms 14980 KB Output is correct
20 Correct 256 ms 29292 KB Output is correct
21 Correct 225 ms 29676 KB Output is correct
22 Correct 49 ms 13124 KB Output is correct
23 Correct 80 ms 13772 KB Output is correct
24 Correct 53 ms 12984 KB Output is correct
25 Correct 54 ms 13116 KB Output is correct
26 Correct 72 ms 11968 KB Output is correct
27 Correct 80 ms 14900 KB Output is correct
28 Correct 49 ms 13124 KB Output is correct
29 Correct 80 ms 14988 KB Output is correct
30 Correct 52 ms 13124 KB Output is correct
31 Correct 85 ms 14968 KB Output is correct

Subtask #5
0 / 46.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4444 KB Output is correct
2 Correct 10 ms 4696 KB Output is correct
3 Correct 10 ms 4444 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 10 ms 4684 KB Output is correct
6 Correct 9 ms 4444 KB Output is correct
7 Correct 1 ms 4444 KB Output is correct
8 Correct 1 ms 4444 KB Output is correct
9 Correct 23 ms 4696 KB Output is correct
10 Correct 11 ms 4664 KB Output is correct
11 Correct 22 ms 4444 KB Output is correct
12 Correct 10 ms 4696 KB Output is correct
13 Correct 23 ms 4444 KB Output is correct
14 Correct 22 ms 4444 KB Output is correct
15 Correct 23 ms 4692 KB Output is correct
16 Execution timed out 4064 ms 11108 KB Time limit exceeded
17 Halted 0 ms 0 KB -