Submission #806717

#	Time	Username	Problem	Language	Result	Execution time	Memory
806717		TheSahib	Cyberland (APIO23_cyberland)	C++17	68 / 100	3067 ms	91624 KiB

cyberland

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

#define ll long long
#define pii pair<int, char>
using namespace std;

const ll oo = 1e18;
const int MAX = 1e5 + 5;

struct edge{
    int u, c;
};

int n, k, f;
int A[MAX];
vector<edge> g[MAX];
bool visited[MAX];

vector<int> starts;
void dfs(int node){
    visited[node] = 1;
    for(auto& e:g[node]){
        if(visited[e.u]) continue;
        dfs(e.u);
    }
}

double dist[MAX][32];
bool comp(pii a, pii b){
    return dist[a.first][a.second] <= dist[b.first][b.second];
}

void dijkstra(){
    set<pii, decltype(&comp)> st(&comp);
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j <= k; j++)
        {
            dist[i][j] = oo;
        }
    }
    
    for(int a:starts){
        dist[a][k] = 0;
        st.insert({a, k});
    }
    while(!st.empty()){
        
        int node = st.begin()->first;
        int l = st.begin()->second;
        double d = dist[node][l];
        st.erase(st.begin());


        for(auto& e:g[node]){
            double b = d + e.c;
            
            if(b < dist[e.u][l]){
                st.erase({e.u, l});
                dist[e.u][l] = b;
                st.insert({e.u, l});
            }
            if(l == 0 || A[e.u] != 2) continue;
            if(b / 2 < dist[e.u][l - 1]){
                st.erase({e.u, l - 1});
                dist[e.u][l - 1] = b / 2;
                st.insert({e.u, l - 1});
            }
        }
    }
}


double solve(int N, int M, int K, int H, vector<int> x, vector<int> y, vector<int> c, vector<int> arr) {
    n = N;
    k = K;
    f = H;
    starts.clear();
    for (int i = 0; i < n; i++)
    {
        A[i] = arr[i];
        g[i].clear();
        visited[i] = 0;
    }
    
    for (int i = 0; i < M; i++)
    {
        g[x[i]].push_back({y[i], c[i]});
        g[y[i]].push_back({x[i], c[i]});
    }
    g[f].clear();
    dfs(0);
    starts.push_back(0);
    for (int i = 0; i < n; i++)
    {
        if(visited[i] && A[i] == 0){
            starts.push_back(i);
        }
    }
    dijkstra();
    double ans = oo;
    for(int i = 0; i <= k; ++i){
        ans = min(ans, dist[f][i]);
    }
    if(ans == oo){
        return -1;
    }
    else{
        return ans;
    }
}

Compilation message (stderr)

cyberland.cpp: In function 'bool comp(std::pair<int, char>, std::pair<int, char>)':
cyberland.cpp:31:28: warning: array subscript has type 'char' [-Wchar-subscripts]
   31 |     return dist[a.first][a.second] <= dist[b.first][b.second];
      |                          ~~^~~~~~
cyberland.cpp:31:55: warning: array subscript has type 'char' [-Wchar-subscripts]
   31 |     return dist[a.first][a.second] <= dist[b.first][b.second];
      |                                                     ~~^~~~~~

• 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: 0 / 29
• Subtask 8: 0 / 3