Submission #1237412

#	Time	Username	Problem	Language	Result	Execution time	Memory
1237412		Gray	Text editor (CEOI24_editor)	C++20	56 / 100	4101 ms	521120 KiB

Main

#pragma GCC optimize("Ofast,unroll-loops")
#include<bits/stdc++.h>

#define ll int
#define ff first
#define ss second
#define ln "\n"

using namespace std;
const ll INF = 2e9;

void solve(){
    ll n; cin >> n;
    ll sr, sc; cin >> sr >> sc;
    ll er, ec; cin >> er >> ec;
    vector<ll> a(n);
    for (ll i=0; i<n; i++){
        cin >> a[i]; a[i]++;
    }
    vector<pair<ll, ll>> pts;
    pts.push_back({er, ec});
    pts.push_back({sr, sc});
    for (ll i=0; i<n; i++){
        pts.push_back({i+1, 1}); pts.push_back({i+1, a[i]});
        if (a[i]>sc and sc>1) pts.push_back({i+1, sc});
        if (a[i]>ec and ec>1) pts.push_back({i+1, ec});
        if (i+1<n and a[i+1]<=a[i]) pts.push_back({i+1, a[i+1]});
        if (i and a[i-1]<=a[i]) pts.push_back({i+1, a[i-1]});
    }
    sort(pts.begin(), pts.end());
    pts.erase(unique(pts.begin(), pts.end()), pts.end());

    auto getid = [&](ll r, ll c){
        ll res=lower_bound(pts.begin(), pts.end(), make_pair(r, c))-pts.begin();
        if(res>=(ll)pts.size() or pts[res]!=make_pair(r, c)){
            return -1;
        }
        return res;
    };
    vector<vector<pair<ll, ll>>> A(pts.size());

    vector<ll> st, con; 
    for (ll i=n-1; i>=0; i--){
        con.clear(); con.push_back(1); con.push_back(a[i]);
        if (a[i]>sc and sc>1) con.push_back(sc);
        if (a[i]>ec and ec>1) con.push_back(ec);
        if (i+1<n and a[i+1]<=a[i]) con.push_back(a[i+1]);
        if (i and a[i-1]<=a[i]) con.push_back(a[i-1]);
        sort(con.begin(), con.end());
        con.erase(unique(con.begin(), con.end()), con.end());
        // cout << i << ": ";
        // for (auto x: con) cout << x << " ";
        // cout << ln;
        for (ll j=1; j<(ll)con.size(); j++){
            ll from = getid(i+1, con[j-1]), to = getid(i+1, con[j]);
            if (from!=-1 and to!=-1){
                A[from].push_back({to, con[j]-con[j-1]});
                A[to].push_back({from, con[j]-con[j-1]});
            }
        }
        if (i){
            for (ll j=0; j<(ll)con.size(); j++){
                if (con[j]<=a[i-1]) {
                    ll from = getid(i, con[j]), to = getid(i+1, con[j]);
                    if (from!=-1 and to!=-1){
                        A[from].push_back({to, 1});
                        A[to].push_back({from, 1});
                    }
                }
            }
            ll from = getid(i, a[i-1]), to = getid(i+1, 1);
            if (from!=-1 and to!=-1){
                A[from].push_back({to, 1});
                A[to].push_back({from, 1});
            }
        }
        if (i+1<n){
            for (ll j=0; j<(ll)con.size(); j++){
                if (con[j]<=a[i+1]) {
                    ll from = getid(i+1, con[j]), to = getid(i+2, con[j]);
                    if (from!=-1 and to!=-1){
                        A[from].push_back({to, 1});
                        A[to].push_back({from, 1});
                    }
                }
            }
        }
        while(!st.empty() and a[st.back()]>=a[i]) st.pop_back();
        if (!st.empty()){
            ll lim=a[st.back()];
            for (ll j=con.size()-1; j>=0 and con[j]>lim; j--){
                ll from = getid(i+1, con[j]), to = getid(st.back()+1, a[st.back()]);
                A[from].push_back({to, st.back()-i});
            }
        }
        st.push_back(i);
    }
    st.clear();
    for (ll i=0; i<n; i++){
        con.clear(); con.push_back(1); con.push_back(a[i]);
        if (a[i]>sc and sc>1) con.push_back(sc);
        if (a[i]>ec and ec>1) con.push_back(ec);
        if (i+1<n and a[i+1]<=a[i]) con.push_back(a[i+1]);
        if (i and a[i-1]<=a[i]) con.push_back(a[i-1]);
        sort(con.begin(), con.end());
        con.erase(unique(con.begin(), con.end()), con.end());
        
        while(!st.empty() and a[st.back()]>=a[i]) st.pop_back();
        if (!st.empty()){
            ll lim=a[st.back()];
            for (ll j=con.size()-1; j>=0 and con[j]>lim; j--){
                ll from = getid(i+1, con[j]), to = getid(st.back()+1, a[st.back()]);
                A[from].push_back({to, i-st.back()});
            }
        }
        st.push_back(i);
    }
    priority_queue<pair<ll, ll>, vector<pair<ll, ll>>, greater<pair<ll, ll>>> que;
    vector<ll> dist(pts.size(), INF), vis(pts.size()); ll root=getid(sr, sc);
    que.push({0, root}); dist[root]=0;
    while (!que.empty()){
        auto cur = que.top(); que.pop();
        ll u = cur.ss, sw = cur.ff;
        if (vis[u]) continue;
        vis[u]=1;
        for (auto [v, w]:A[u]){
            if (dist[v]>w+sw){
                que.push({w+sw, v}); dist[v]=w+sw;
            }
        }
    }
    cout << dist[getid(er, ec)] << ln;
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ll t=1; 
    // cin >> t;
    while (t--){
        solve();
    }
}

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 14 / 14
• Subtask 3: 26 / 26
• Subtask 4: 11 / 11
• Subtask 5: 0 / 44