Submission #978227

#	Time	Username	Problem	Language	Result	Execution time	Memory
978227		Tsagana	Cyberland (APIO23_cyberland)	C++17	8 / 100	246 ms	10176 KiB

cyberland

#include "cyberland.h"

// START 
#include <bits/stdc++.h>

#define IOS ios_base::sync_with_stdio(false);cin.tie();cout.tie();
#define all(x) x.begin(), x.end()
#define vi vector<int>
#define pi pair<int, int >
#define lb lower_bound
#define ub upper_bound
#define pb push_back
#define eb emplace_back
#define mset multiset
#define F first
#define S second
#define pid pair<int, double>
#define pdi pair<double, int>
 
using namespace std;
 
vector<pid> adj[100005];
double mindis[100005];
bool reach[100005];
int h, n;
 
void dfs(int u) {
    reach[u] = 1;
    if (u == h) return;
    for (auto [v, w]: adj[u]) {
        if (!reach[v]) dfs(v);
    }
}
 
void dij(vector<int> &arr) {
    priority_queue<pdi> pq;
    for (int i = 0; i < n; i++) {
        if (reach[i] && mindis[i] < 1e18) pq.push({mindis[i], i});
    }
    vector<bool> vis(n, 0);
    while(!pq.empty()) {
        int u = pq.top().S;
        pq.pop();
        if (vis[u]) continue;
        vis[u] = 1;
        if (u == h) continue;
        for (auto [v, w]: adj[u]) {
            if (reach[v] && !vis[v] && mindis[v] > mindis[u] + w) {
                mindis[v] = mindis[u] + w;
                pq.push({mindis[v], v});
            }
        }
    }
    vector<pid> tmp;
    for (int u = 0; u < n; u++) {
        double mn = mindis[u];
        if (reach[u] && arr[u] == 2) {
            for(auto [v, w]: adj[u]) {
                if (reach[v] && v != h) mn = min(mn, (mindis[v] + w) / 2.0);
            }
        }
        if(mn < mindis[u]) tmp.pb({u, mn});
    }
    for (auto [u, dis]: tmp) {
        mindis[u] = min(mindis[u], dis);
    }
}
 
double solve(int N, int M, int K, int H, vector<int> x, vector<int> y, vector<int> c, vector<int> arr) {
    h = H; n = N;
    K = min(K, 70);
    for (int i = 0; i < N; i++) {
        adj[i].clear();
        reach[i] = 0;
        mindis[i] = 1e18;
    }

    for (int i = 0; i < M; i++) {
        adj[x[i]].pb({y[i], (double)c[i]});
        adj[y[i]].pb({x[i], (double)c[i]});
    }
    dfs(0);
    if (!reach[H]) return -1;
    mindis[0] = 0;
    for (int i = 1; i < N; i++) {
        if (reach[i] && arr[i] == 0) {
            mindis[i] = 0;
        }
    }
    for (int i = 0; i <= K; i++) dij(arr);
    return mindis[H];
}
//END

• Subtask 1: 0 / 5
• Subtask 2: 8 / 8
• Subtask 3: 0 / 13
• Subtask 4: 0 / 19
• Subtask 5: 0 / 7
• Subtask 6: 0 / 16
• Subtask 7: 0 / 29
• Subtask 8: 0 / 3