Submission #1271161

#	Time	Username	Problem	Language	Result	Execution time	Memory
1271161		abdelhakim	Cyberland (APIO23_cyberland)	C++20	100 / 100	1178 ms	24704 KiB

cyberland

#include "cyberland.h"
#include <bits/stdc++.h>

#define ll long long
#define inf 1e18
#define dbg(x) cerr<<#x<<' '<<x<<endl;
using namespace std;
vector<bool> vis;
vector<ll> zeros;
vector<ll> tws;
vector<vector<pair<ll,long double>>> adj;
void dfs(ll node, vector<int>& arr, ll h)
{
    vis[node]=true;
    if(node==h) return;
    if(arr[node]==0) zeros.push_back(node);
    else if(arr[node]==2) tws.push_back(node);
    for (auto &&e : adj[node])
    {
        if(!vis[e.first]) 
        {
            dfs(e.first,arr,h);
        }
    }  
}
double solve(int N, int M, int K, int H, std::vector<int> x, std::vector<int> y, std::vector<int> c, std::vector<int> arr) {
    vis.assign(N,false);
    adj.assign(N,vector<pair<ll,long double>>());
    zeros.clear();
    tws.clear();
    zeros.push_back(0);
    for (int i=0;i<M;i++)
    {
        adj[x[i]].push_back({y[i],c[i]});
        adj[y[i]].push_back({x[i],c[i]});
    }
    dfs(0,arr,H);
    if(!vis[H]) return -1;
    vector<long double> dist(N,inf);
    priority_queue<pair<long double,int>,vector<pair<long double,int>>,greater<pair<long double,int>>> pq;
    for (auto &&e : zeros)
    {
        dist[e]=0;
        pq.push({0,e});
    }
    
    auto dij=[&]()
    {
        while(!pq.empty())
        {
            ll nd=pq.top().second;
            pq.pop();
            for (auto &&e : adj[nd])
            {
                if(dist[e.first] > dist[nd]+e.second)
                {
                    dist[e.first]=dist[nd]+e.second;
                    if(e.first!=H)pq.push({dist[e.first],e.first});
                }
            }
        }
    };
    dij();
    
    for (int i=0;i<min(70,K);i++)
    {
        vector<long double> prev=dist;
        for (auto &&e : tws)
        {
            long double val = prev[e]/2;
            for (auto &&ei : adj[e])
            {
                dist[ei.first]=min(dist[ei.first],val+ei.second);
                if(ei.first!=H)
                pq.push({dist[ei.first],ei.first});
            }
        }
        dij();
    }
    return dist[H];
}

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