Submission #490786

#	Time	Username	Problem	Language	Result	Execution time	Memory
490786		hollwo_pelw	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	125 ms	65452 KiB

skyscraper

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

const int N = 3e4 + 5;

int n, m, dis[N];
vector<pair<int, int>> adj[N];
set<int> doge[N];

int s = -1, t = -1;

signed main() {
    cin.tie(0), cout.tie(0) -> sync_with_stdio(0);
    
    cin >> n >> m;
    
    memset(dis, 0x3f, sizeof dis);
    
    for (int p, d; m --; ) {
        cin >> p >> d;
        if (s == -1) s = p;
        else if (t == -1) t = p;
        doge[p].insert(d);
    }
    
    for (int i = 0; i < n; i++) {
        for (auto d : doge[i]) {
            for (int j = i + d, w = 1; j <  n; j += d, w++) {
                // cout << i << ' ' << j << ' ' << w << '\n';
                adj[i].emplace_back(j, w);
                if (doge[j].count(d)) break ;
            }
            for (int j = i - d, w = 1; j >= 0; j -= d, w++) {
                // cout << i << ' ' << j << ' ' << w << '\n';
                adj[i].emplace_back(j, w);
                if (doge[j].count(d)) break ;
            }
        }
    }
    
    priority_queue<pair<int, int>> pq;
    pq.emplace(dis[s] = 0, s);
    
    while (!pq.empty()) {
        int d = -pq.top().first, u = pq.top().second; pq.pop();
        if (d != dis[u]) continue ;
        
        if (u == t)
            return cout << d, 0;
        
        for (auto [v, w] : adj[u]) {
            if (dis[v] > d + w)
                pq.emplace(-(dis[v] = d + w), v);
        }
    }
    
    cout << -1;
}

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