Submission #1288166

#	Time	Username	Problem	Language	Result	Execution time	Memory
1288166		gustavo_d	Jakarta Skyscrapers (APIO15_skyscraper)	C++20	36 / 100	211 ms	294796 KiB

skyscraper

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

#pragma GCC optimize("O3,inline-functions")

const int MAXN = 2000;
const int MAXM = 30000;

bool liberated[MAXN];
int pos[MAXM], jump[MAXM];
vector<int> in[MAXN];
int dist[MAXN][MAXM];
bool vis[MAXN][MAXM];

queue<pair<int, int>> bfs;
int n;

void liberate(int i, int d) {
    if (liberated[i]) return;
    liberated[i] = true;
    for (int v : in[i]) {
        if (vis[i][v]) continue;
        dist[i][v] = d;
        bfs.push({i, v});
        vis[i][v] = true;
    }
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL);

    int m; cin >> n >> m;
    for (int i=0; i<m; i++) {
        cin >> pos[i] >> jump[i];
        if (i == 1) continue;
        in[pos[i]].push_back(i);
    }

    liberate(pos[0], 0);
    while (!bfs.empty()) {
        auto [p, v] = bfs.front();
        // cout << p << ' ' << v << ':' << dist[p][v] << '\n';
        bfs.pop();
        if (p == pos[1]) {
            cout << dist[p][v] << '\n';
            return 0;
        }
        if (p - jump[v] >= 0 and !vis[p-jump[v]][v]) {
            vis[p-jump[v]][v] = true;
            dist[p-jump[v]][v] = dist[p][v] + 1;
            bfs.push({p - jump[v], v});
            liberate(p - jump[v], dist[p][v] + 1);
        }
        if (p + jump[v] < n and !vis[p+jump[v]][v]) {
            vis[p+jump[v]][v] = true;
            dist[p+jump[v]][v] = dist[p][v] + 1;
            bfs.push({p + jump[v], v});
            liberate(p + jump[v], dist[p][v] + 1);
        }
    }
    cout << -1 << '\n';

    return 0;
}

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