Submission #976007

#	Time	Username	Problem	Language	Result	Execution time	Memory
976007		nnin	Cyberland (APIO23_cyberland)	C++17	97 / 100	663 ms	62372 KiB

cyberland

#include "cyberland.h"
#include <bits/stdc++.h>
using namespace std;
#define pid pair<int,double>
#define f first
#define s second
#define A pair<double, pair<int,int>>
 
vector<pid> adj[100005];
bool reach[100005];
int HH;
 
void dfs(int u) {
    reach[u] = 1;
    if(u==HH) return;
    for(auto [v, w]:adj[u]) {
        if(!reach[v]) dfs(v);
    }
}
 
double mindis[100005][55];
 
double solve(int N, int M, int K, int H, vector<int> x, vector<int> y, vector<int> c, vector<int> arr) {
    K = min(K, 50);
    HH = H;
    for(int i=0;i<N;i++) {
        adj[i].clear();
        reach[i] = 0;
        for(int j=0;j<=K;j++) {
            mindis[i][j] = 1e18;
        }
    }
    for(int i=0;i<M;i++) {
        adj[x[i]].push_back({y[i], (double)c[i]});
        adj[y[i]].push_back({x[i], (double)c[i]});
    }
    dfs(0);
    if(!reach[H]) return -1;
    priority_queue<A, vector<A>, greater<A>> pq;
    pq.push({0, {0, 0}});
    mindis[0][0] = 0;
    for(int i=1;i<N;i++) {
        if(reach[i] && arr[i]==0) {
            pq.push({0, {i, 0}});
            mindis[i][0] = 0;
        }
    }
    while(!pq.empty()) {
        double dis = pq.top().f;
        auto [u, ct] = pq.top().s;
        pq.pop();
        if(mindis[u][ct]!=dis || u==H) continue;
        for(auto [v, w]:adj[u]) {
            if(arr[v]>0 && mindis[v][ct]>dis+w) {
                mindis[v][ct] = dis+w;
                pq.push({mindis[v][ct], {v, ct}});
            }
            if(arr[v]==2 && ct<K && mindis[v][ct+1]>(dis+w)/2) {
                mindis[v][ct+1] = (dis+w)/2;
                pq.push({mindis[v][ct+1], {v, ct+1}});
            }
        }
    }
    double ret = 1e18;
    for(int i=0;i<=K;i++) ret = min(ret, mindis[H][i]);
    return ret;
}

• 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: 0 / 3