Submission #1170199

#	Time	Username	Problem	Language	Result	Execution time	Memory
1170199		vibeduck	Airplane (NOI23_airplane)	C++17	0 / 100	56 ms	126276 KiB

Main

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

#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define int long long
#define all(x) (x).begin(), (x).end()

typedef long double ld;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<bool> vb;
typedef vector<vector<int>> vvi;
typedef vector<vector<bool>> vvb;
typedef vector<vector<ll>> vvll;
typedef vector<string> vs;
typedef vector<vector<string>> vvs;
typedef vector<char> vc;
typedef vector<vector<char>> vvc;
typedef map<int, int> mii;
typedef unordered_map<int, int> umii;

const int mod = 1e9 + 7;
const int inf = INTMAX_MAX;
const bool tc = false;

int enc(int x, int y) {
    return x * 2001 + y;
}

pii dec(int x) {
    return {x / 2001, x % 2001};
}

const int mxn = 2001 * 2001;
vector<int> adj[mxn]; int d[mxn];

inline void solve() {
    int n, m;
    cin >> n >> m;
    memset(d, -1, sizeof(d));
    vi a(n); for (int i = 0; i < n; i++) cin >> a[i];
    vector<pii> edges; for (int i = 0; i < m; i++) {
        int u, v; cin >> u >> v; u--; v--;
        edges.pb({u, v});
    }

    for (int h = 0; h <= 2000; h++) {
        for (auto &x : edges) {
            if (h < a[x.fi]) continue;
            if (h >= a[x.se]) adj[enc(x.fi, h)].pb(enc(x.se, h));
            if (h) {
                if (h - 1 >= a[x.se]) adj[enc(x.fi, h)].pb(enc(x.se, h - 1));
                if (h - 1 >= a[x.fi]) adj[enc(x.fi, h)].pb(enc(x.fi, h - 1));
            }
            if (h != 2000) {
                adj[enc(x.fi, h)].pb(enc(x.se, h + 1));
                adj[enc(x.fi, h)].pb(enc(x.fi, h + 1));
            }

            swap(x.fi, x.se);

            if (h < a[x.fi]) {
                swap(x.fi, x.se);
                continue;
            }
            if (h >= a[x.se]) adj[enc(x.fi, h)].pb(enc(x.se, h));
            if (h) {
                if (h - 1 >= a[x.se]) adj[enc(x.fi, h)].pb(enc(x.se, h - 1));
                if (h - 1 >= a[x.fi]) adj[enc(x.fi, h)].pb(enc(x.fi, h - 1));
            }
            if (h != 2000) {
                adj[enc(x.fi, h)].pb(enc(x.se, h + 1));
                adj[enc(x.fi, h)].pb(enc(x.fi, h + 1));
            }

            swap(x.fi, x.se);
        }
    }

    queue<pii> bfs;
    bfs.push({enc(0, 0), 0});
    while (bfs.size()) {
        auto cur = bfs.front();
        bfs.pop();
        int u = cur.fi; int dis = cur.se;

        //if (dec(u).fi == n - 1) cout << dec(u).fi << " " << dec(u).se << "\n";

        if (d[u] != -1) continue;

        d[u] = dis;
        for (auto &neighbour : adj[u]) {
            if (d[neighbour] != -1) continue;
            bfs.push({neighbour, dis + 1});
        }
    }
    cout << d[enc(n - 1, 0)] << '\n';
}

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

signed main() {
    ios::sync_with_stdio(false);
    cout.tie(0);
    cin.tie(0);
    //setIO();

    int t = 1;
    if (tc) {
        cin >> t;
    }

    while (t--) {
        solve();
    }
}

Compilation message (stderr)

Main.cpp: In function 'void setIO(std::string)':
Main.cpp:108:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  108 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:109:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  109 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 22
• Subtask 2: 0 / 10
• Subtask 3: 0 / 31
• Subtask 4: 0 / 37