Submission #565671

#	Time	Username	Problem	Language	Result	Execution time	Memory
565671		RealSnake	Evacuation plan (IZhO18_plan)	C++14	0 / 100	4091 ms	117228 KiB

plan

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

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

#define ll long long
#define mod 1000000007

ofstream fout(".out");
ifstream fin(".in");

vector<pair<int, int>> v[100001];
int d[100001];
bool vis[100001];
int s, t;

int dfs(int x) {
    if(x == t)
        return d[x];
    vis[x] = 1;
    int mx = 0;
    for(auto i : v[x]) {
        if(d[i.first] && !vis[i.first])
            mx = max(mx, dfs(i.first));
    }
    vis[x] = 0;
    if(mx == 0)
        mx = 1e9;
    return min(d[x], mx);
}

void dijkstra(int y) {
    set<pair<int, int>> s;
    s.insert({0, y});
    while(s.size()) {
        pair<int, int> p = *s.begin();
        s.erase(s.begin());
        int x = p.second;
        int cost = p.first;
        if(d[x] == 0) {
            d[y] = cost;
            return;
        }
        for(auto i : v[x])
            s.insert({cost + i.second, i.first});
    }
}

signed main() {

    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    int n, m;
    cin >> n >> m;
    for(int i = 1; i <= n; i++)
        d[i] = 1e9;
    for(int i = 0; i < m; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        v[a].push_back({b, c});
        v[b].push_back({a, c});
    }
    int k;
    cin >> k;
    for(int i = 0; i < k; i++) {
        int x;
        cin >> x;
        d[x] = 0;
    }
    for(int i = 1; i <= n; i++) {
        if(d[i])
            dijkstra(i);
    }
    int q;
    cin >> q;
    while(q--) {
        cin >> s >> t;
        bool b = 0;
        for(auto i : v[s]) {
            if(i.first == t) {
                b = 1;
                break;
            }
        }
        if(b) {
            cout << min(d[s], d[t]) << "\n";
            continue;
        }
        cout << dfs(s) << "\n";
    }

    return 0;
}

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