| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 569018 | Alan | Jakarta Skyscrapers (APIO15_skyscraper) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
vector<ll> adj[30000];
struct node {
ll u, di, vel;
};
ll main() {
unordered_map<ll, bool> vis;
ll n, m, b, p, d0, d1;
cin >> n >> m;
for (ll i = 0; i < m; i++) {
cin >> b >> p;
if (i == 0) d0 = b;
if (i == 1) d1 = b;
if (0 <= b+p && b+p < n) adj[b].push_back(p);
if (0 <= b-p && b-p < n) adj[b].push_back(-p);
}
queue<node> bfs;
bfs.push({d0, 0, 0});
while (!bfs.empty()) {
auto& [u, di, vel] = bfs.front();
if (u == d1) {
cout << di << "\n";
return 0;
}
bfs.pop();
if (!vis[(u<<16)+vel] && u+vel >= 0 && u+vel < n) bfs.push({u+vel, di+1, vel}), vis[(u<<16)+vel] = true;
for (auto& s : adj[u]) if (!vis[(u<<16)+s]) bfs.push({u+s, di+1, s}), vis[(u<<16)+s] = true;
}
cout << "-1\n";
return 0;
}