oj.uz

답안 #893955

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
893955 2023-12-27T17:44:33 Z borisAngelov Evacuation plan (IZhO18_plan) C++17
41 / 100
 4000 ms 36396 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 > 0.1)
    {
        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

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 7260 KB Output is correct
2 Correct 2 ms 7516 KB Output is correct
3 Correct 3 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 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 2 ms 7512 KB Output is correct
13 Correct 5 ms 7516 KB Output is correct
14 Correct 5 ms 7516 KB Output is correct
15 Correct 7 ms 7668 KB Output is correct

Subtask #2
0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 7260 KB Output is correct
2 Correct 2 ms 7516 KB Output is correct
3 Correct 3 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 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 2 ms 7512 KB Output is correct
13 Correct 5 ms 7516 KB Output is correct
14 Correct 5 ms 7516 KB Output is correct
15 Correct 7 ms 7668 KB Output is correct
16 Correct 3173 ms 19164 KB Output is correct
17 Correct 2243 ms 36396 KB Output is correct
18 Correct 202 ms 10388 KB Output is correct
19 Correct 79 ms 29712 KB Output is correct
20 Correct 2304 ms 36212 KB Output is correct
21 Correct 309 ms 31424 KB Output is correct
22 Execution timed out 4059 ms 19832 KB Time limit exceeded
23 Halted 0 ms 0 KB -

Subtask #3
12.0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 7516 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 1 ms 7516 KB Output is correct
6 Correct 2 ms 7516 KB Output is correct
7 Correct 1 ms 7516 KB Output is correct
8 Correct 2 ms 7260 KB Output is correct
9 Correct 1 ms 7516 KB Output is correct
10 Correct 2 ms 7516 KB Output is correct

Subtask #4
19.0 / 19.0

# 결과 실행 시간 메모리 Grader output
1 Correct 123 ms 18116 KB Output is correct
2 Correct 268 ms 30576 KB Output is correct
3 Correct 281 ms 30296 KB Output is correct
4 Correct 98 ms 16336 KB Output is correct
5 Correct 286 ms 30816 KB Output is correct
6 Correct 256 ms 29780 KB Output is correct
7 Correct 265 ms 30528 KB Output is correct
8 Correct 277 ms 29656 KB Output is correct
9 Correct 244 ms 29632 KB Output is correct
10 Correct 270 ms 30660 KB Output is correct
11 Correct 290 ms 30668 KB Output is correct
12 Correct 256 ms 30656 KB Output is correct
13 Correct 263 ms 30268 KB Output is correct
14 Correct 242 ms 29916 KB Output is correct
15 Correct 270 ms 30912 KB Output is correct
16 Correct 269 ms 30308 KB Output is correct
17 Correct 271 ms 29640 KB Output is correct
18 Correct 275 ms 29864 KB Output is correct
19 Correct 85 ms 16392 KB Output is correct
20 Correct 269 ms 30408 KB Output is correct
21 Correct 203 ms 28192 KB Output is correct
22 Correct 60 ms 15220 KB Output is correct
23 Correct 132 ms 15592 KB Output is correct
24 Correct 50 ms 15172 KB Output is correct
25 Correct 49 ms 15428 KB Output is correct
26 Correct 99 ms 15260 KB Output is correct
27 Correct 95 ms 16276 KB Output is correct
28 Correct 53 ms 15168 KB Output is correct
29 Correct 98 ms 16348 KB Output is correct
30 Correct 49 ms 15424 KB Output is correct
31 Correct 93 ms 16336 KB Output is correct

Subtask #5
0 / 46.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 7260 KB Output is correct
2 Correct 2 ms 7516 KB Output is correct
3 Correct 3 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 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 2 ms 7512 KB Output is correct
13 Correct 5 ms 7516 KB Output is correct
14 Correct 5 ms 7516 KB Output is correct
15 Correct 7 ms 7668 KB Output is correct
16 Correct 3173 ms 19164 KB Output is correct
17 Correct 2243 ms 36396 KB Output is correct
18 Correct 202 ms 10388 KB Output is correct
19 Correct 79 ms 29712 KB Output is correct
20 Correct 2304 ms 36212 KB Output is correct
21 Correct 309 ms 31424 KB Output is correct
22 Execution timed out 4059 ms 19832 KB Time limit exceeded
23 Halted 0 ms 0 KB -