Submission #565712

#	Time	Username	Problem	Language	Result	Execution time	Memory
565712		1zaid1	Evacuation plan (IZhO18_plan)	C++17	0 / 100	175 ms	95676 KiB

plan

#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define int long long
typedef long long ll;
const int M = 2e6 + 5, MOD = 1e9+7;
vector<pair<int, int>> node[M];
int dist[M], dist2[M], n, vis[M];
 
void dij1() {
    for (int i = 1; i <= n; i++) dist[i] = INT_MAX;
    priority_queue<pair<int, int>> q;
    int k;
    cin >> k;
    for (int i = 1; i <= k; i++) {
        int a; cin >> a;
        dist[a] = 0;
        q.push({0, a});
    }
 
    while (!q.empty()) {
        auto [new_dist, new_node] = q.top(); q.pop();
        new_dist = -new_dist;
        if (dist[new_node] < new_dist) continue;
        for (auto [n, d]:node[new_node]) {
            if (new_dist + d < dist[n]) {
                dist[n] = new_dist + d;
                q.push({-dist[n], n});
            }
        }
    }
}

int rec(int a, int b) {
    if (a == b) return dist[a];
    int mn = 0;
    for (auto [i,x]:node[a]) {
        if (!vis[i]) {
            vis[i] = 1;
            mn = max(mn, rec(i, b));
            vis[i] = 0;
        }
    }

    return min(mn, dist[a]);
}

signed main() {
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    srand(time(0));
    
    int m;
    cin >> n >> m;

    map<pair<int, int>, bool> ok;
 
    for (int i = 1; i <= m; i++) {
        int a, b, c;
        cin >> a >> b >> c;
 
        node[a].push_back({b, c});
        node[b].push_back({a, c});
    }
 
    dij1();
 
    int t;
    cin >> t;

    if (n <= 15) {
        int ans[n][n];
        for (auto&i:ans) for (int&j:i) j = 0;
        for (int i = 1; i <= n; i++) {
            for (int j = i+1; j <= n; j++) ans[i][j] = ans[j][i] = rec(i, j);
        }

        while (t--) {
            int a, b;
            cin >> a >> b;
            cout << ans[a][b] << endl;
        }

        return 0;
    }

    while (t--) {
        int a, b;
        cin >> a >> b;
 
        cout << min(dist[a], dist[b]) << endl;
    }
 
    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
*/

• Subtask 1: 0 / 10
• Subtask 2: 0 / 13
• Subtask 3: 0 / 12
• Subtask 4: 0 / 19
• Subtask 5: 0 / 46