Submission #1091658

#	Time	Username	Problem	Language	Result	Execution time	Memory
1091658		raphaelp	Sightseeing (NOI14_sightseeing)	C++14	15 / 25	3599 ms	212968 KiB

sightseeing

#include <bits/stdc++.h>
using namespace std;

vector<int> p;
int find(int x) { return (p[x] == x) ? x : p[x] = find(p[x]); }
void dfs(int x, int p, vector<vector<pair<int, int>>> &AR, vector<int> &dist, int cur)
{
    dist[x] = cur;
    for (int i = 0; i < AR[x].size(); i++)
    {
        if (AR[x][i].first == p)
            continue;
        dfs(AR[x][i].first, x, AR, dist, min(cur, AR[x][i].second));
    }
}
int main()
{
    int N, M, Q;
    cin >> N >> M >> Q;
    vector<vector<pair<int, int>>> buckets(1000010);
    for (int i = 0; i < M; i++)
    {
        int a, b, c;
        cin >> a >> b >> c;
        a--, b--;
        buckets[c].push_back({a, b});
    }
    p.assign(N, 0);
    for (int i = 0; i < N; i++)
        p[i] = i;
    vector<int> dist(N);
    vector<vector<int>> contains(N);
    vector<vector<pair<int, int>>> AR(N);
    for (int i = 0; i < N; i++)
        contains[i].push_back(i);
    for (int i = 1000000; i >= 0; i--)
    {
        for (int j = 0; j < buckets[i].size(); j++)
        {
            int x = find(buckets[i][j].first), y = find(buckets[i][j].second);
            if (x == y)
                continue;
            if (contains[x].size() > contains[y].size())
                swap(x, y);
            if (find(0) == x)
                swap(x, y);
            p[x] = y;
            AR[buckets[i][j].first].push_back({buckets[i][j].second, i});
            AR[buckets[i][j].second].push_back({buckets[i][j].first, i});
        }
    }
    if (M < 3500000)
        dfs(0, 0, AR, dist, 1000000000);

    for (int i = 0; i < Q; i++)
    {
        int x;
        cin >> x;
        cout << dist[x - 1] << '\n';
    }
}

Compilation message (stderr)

sightseeing.cpp: In function 'void dfs(int, int, std::vector<std::vector<std::pair<int, int> > >&, std::vector<int>&, int)':
sightseeing.cpp:9:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |     for (int i = 0; i < AR[x].size(); i++)
      |                     ~~^~~~~~~~~~~~~~
sightseeing.cpp: In function 'int main()':
sightseeing.cpp:38:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |         for (int j = 0; j < buckets[i].size(); j++)
      |                         ~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 5 / 5
• Subtask 3: 6 / 6
• Subtask 4: 0 / 10