Submission #1188613

#	Time	Username	Problem	Language	Result	Execution time	Memory
1188613		prism7k	Crocodile's Underground City (IOI11_crocodile)	C++20	0 / 100	0 ms	320 KiB

crocodile

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

using ll = long long;
const ll INF = 2e16;

int travel_plan(int N, int M, int R[][2], int L[], int K, int P[]) {
    vector<vector<pair<int,int>>> adj(N);
    vector<ll> dist(N, INF), f(N, INF);
	
	for(int i = 0; i < M; ++i) {
		int u = R[i][0], v = R[i][1];
		int w = L[i];
		adj[u].push_back({v, w});
		adj[v].push_back({u, w});
	}
	
	priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<>> q;
	for(int i = 0; i < K; ++i) { 
		q.push({0LL, P[i]}); 
		dist[P[i]] = 0;
	}
	
	while(!q.empty()) {
		auto[cur_weight, u] = q.top(); q.pop();
		if(cur_weight != dist[u]) continue;
		
		for(auto[v, w] : adj[u]) {
			if(dist[u] + w < dist[v]) {
				dist[v] = dist[u] + w;
				q.push({dist[v], v});
			}
		}
	}
	
    vector<int> idx(N);
    iota(idx.begin(), idx.end(), 0);
    sort(idx.begin(), idx.end(), [&](int a, int b) { return dist[a] < dist[b]; });
    
    for(int u: idx) {
        if(dist[u] == 0) {
            f[u] = 0;
            continue;
        }
        ll best = INF, second = INF;
        for(auto [v,w]: adj[u]){
            if(dist[v] < dist[u]){
                ll cand = f[v] + w;
                if(cand < best){
                    second = best;
                    best = cand;
                } else if(cand < second){
                    second = cand;
                }
            }
        }
        if(second < INF){
            f[u] = second;
        }
    }
    
    return f[0];
}

• Subtask 1: 0 / 46
• Subtask 2: 0 / 43
• Subtask 3: 0 / 11