Submission #449540

#	Time	Username	Problem	Language	Result	Execution time	Memory
449540		zxcvbnm	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	57 / 100	1094 ms	24732 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define sky first
#define pow second
const int nax = 30005;
const int INF = 1e9 + 5;
vector<pii> adj[nax];
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, m;
    cin >> n >> m;
    vector<pii> a(m);
    for(auto& i : a) {
        cin >> i.sky >> i.pow;
    }


    set<pii> used;
    set<pii> all(a.begin(), a.end());
    for(auto i : a) {
        if (used.count(i)) continue;
        used.insert(i);

        int idx = i.sky + i.pow;
        for(int cost = 1;;cost++) {
            if (idx >= n) break;
            adj[i.sky].push_back({idx, cost});
            if (all.count({idx, i.pow})) break;
//            cout << i.sky << "->" << idx << " " << cost << "\n";
            idx += i.pow;
        }

        idx = i.sky - i.pow;
        for(int cost = 1;;cost++) {
            if (idx < 0) break;
            adj[i.sky].push_back({idx, cost});
            if (all.count({idx, i.pow})) break;
//            cout << i.sky << "->" << idx << " " << cost << "\n";
            idx -= i.pow;
        }
    }

    vector<int> dist(n, INF);
    priority_queue<pii, vector<pii>, greater<pii>> q;
    q.push({a[0].sky, 0});
    dist[a[0].sky] = 0;

    while(!q.empty()) {
        pii v = q.top();
        q.pop();
//        cout << v.sky << " " << v.pow << "\n";
        if (dist[v.sky] < v.pow) continue;

        for(pii u : adj[v.sky]) {
            int cost = u.pow + v.pow;
            if (dist[u.sky] > cost) {
                dist[u.sky] = cost;
                q.push({u.sky, dist[u.sky]});
            }
        }
    }

    cout << (dist[a[1].sky] == INF ? -1 : dist[a[1].sky]) << "\n";
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 0 / 43