Submission #1169780

#	Time	Username	Problem	Language	Result	Execution time	Memory
1169780		Thanhs	Airplane (NOI23_airplane)	C++20	0 / 100	40 ms	15944 KiB

Main

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

#define name "TENBAI"
#define fi first
#define se second
#define int long long
#define endl '\n'
#define setmin(x, y) x = min((x), (y))
#define setmax(x, y) x = max((x), (y))
#define sqr(x) ((x) * (x))

mt19937 hdp(chrono::high_resolution_clock::now().time_since_epoch().count());
int rand(int l, int r){return l + ((hdp() % (r - l + 1)) + r - l + 1) % (r - l + 1);}

const int NM = 2e5 + 5;
const int inf = 1e18;

vector<int> g[NM];
int n, m, a[NM], ans;

void calc(int s, vector<int>& d)
{
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<>> pq;
    d.resize(n + 1, inf);
    d[s] = 0;
    pq.push({0, s});
    while (pq.size())
    {
        int w = pq.top().fi, u = pq.top().se;
        pq.pop();
        if (d[u] != w)
            continue;
        queue<int> st;
        st.push(u);
        while (st.size())
        {
            int U = st.front();
            st.pop();
            for (auto v : g[U])
            {
                if (a[u] >= a[v] && d[v] > d[U] + 1)
                {
                    d[v] = d[U] + 1;
                    st.push(v);
                }
                else if (a[u] < a[v] && d[v] > max(d[U] + 1, w + a[v] - a[u]))
                {
                    d[v] = max(d[U] + 1, w + a[v] - a[u]);
                    pq.push({d[v], v});
                }
            }
        }
    }
}

void solve()
{
    cin >> n >> m;
    for (int i = 1; i <= n; i++)
        cin >> a[i];
    for (int i = 1; i <= m; i++)
    {
        int u, v;
        cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    vector<int> d1, d2;
    calc(1, d1);
    calc(n, d2);
    ans = inf;
    for (int i = 2; i < n; i++)
        setmin(ans, d1[i] + d2[i]);
    cout << ans << endl;
}

signed main()
{
    if (fopen("in.txt", "r")) 
    {
        freopen("in.txt", "r", stdin);
        freopen("out.txt", "w", stdout);
    }
    else if (fopen(name".inp", "r"))
    {
        freopen(name".inp", "r", stdin);
        freopen(name".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
    int tc = 1; 
    // cin >> tc;
    while (tc--)
        solve();
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:82:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |         freopen("in.txt", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
Main.cpp:83:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |         freopen("out.txt", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:87:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   87 |         freopen(name".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:88:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   88 |         freopen(name".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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