Submission #498508

#	Time	Username	Problem	Language	Result	Execution time	Memory
498508		gratus907	주유소 (KOI16_gas)	C++17	73 / 100	2040 ms	55360 KiB

gas

#include <iostream>
#include <vector>
#include <queue>
#pragma GCC optimize("Ofast")
#define ll long long
#define eps 1e-7
#define all(x) ((x).begin()),((x).end())
#define usecppio ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;
using pii = pair<int, int>;

const ll INF = 987654321987654321;
const int MX = 2625;

struct Edge {
    int src, dst, w;
    bool operator<(const Edge &p) const {
        return w > p.w;
    }
};
bool relax(int u, int v, int w, ll dist[])
{
    bool flag = 0;
    if (dist[v] > dist[u] + w && (dist[u] != INF)) {
        flag = true;
        dist[v] = dist[u] + w;
    }
    return flag;
}

int fuel[MX];
ll cost[MX * MX];
vector <Edge> G[MX];

void dijkstra(ll dist[], int start, vector<Edge> graph[])
{
    fill(dist,dist+MX*MX,INF);
    dist[start*2501+fuel[start]] = 0;
    priority_queue<Edge> pq;
    pq.push({0, start,0});
    while(!pq.empty()) {
        Edge x = pq.top();
        pq.pop();
        //printf("Process edge %lld -> %lld (len=%lld)\n",x.src, x.dst, x.w);
        for (auto ed : graph[x.dst]) {
            bool flag = false;
            int max_j = min(2500, fuel[ed.src]);
            for (int j = 1; j <= max_j; j++) {
                int fcost = min(fuel[ed.dst], j);
                if (relax(ed.src*2501+j, ed.dst*2501+fcost, ed.w * j, dist)) {
                    //printf("cost [%lld][%lld] relaxed to %lld\n",ed.dst, fcost, cost[ed.dst*2501+fcost]);
                    flag = true;
                }
            }
            if (flag) pq.push(ed);
        }
    }
}

int32_t main() {
    usecppio
    int n, m; cin >> n >> m;
    for (int i = 1; i <= n; i++) cin >> fuel[i];
    for (int i = 0; i < m; i++) {
        int u, v, w; cin >> u >> v >> w;
        G[u].push_back({u, v, w});
        G[v].push_back({v, u, w});
    }
    dijkstra(cost, 1, G);
    ll ans = INF;
    for (int j = 1; j <= 2500; j++) ans = min(ans, cost[n*2501+j]);
    cout << ans << '\n';
}

• Subtask 1: 18 / 18
• Subtask 2: 15 / 15
• Subtask 3: 16 / 16
• Subtask 4: 24 / 24
• Subtask 5: 0 / 27