Submission #1312504

#	Time	Username	Problem	Language	Result	Execution time	Memory
1312504		syanvu	Exam (eJOI20_exam)	C++20	0 / 100	275 ms	589824 KiB

exam

// #pragma optimize ("g",on)
// #pragma GCC optimize ("inline")
// #pragma GCC optimize ("Ofast")
// #pragma GCC optimize ("unroll-loops")
// #pragma GCC optimize ("03")
#include <bits/stdc++.h>

#define pb push_back
#define SS ios_base::sync_with_stdio(0);cin.tie(nullptr);cout.tie(nullptr);
#define int long long
#define all(v) v.begin(),v.end()
using namespace std;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

const int N = 5000 + 1, inf = 1e9, mod = 998244353;

int n;
int a[N], b[N];

struct tree{
    vector<int> t;
    tree(){
        t.resize(4 * N);
    }
    void upd(int v, int tl, int tr, int pos, int x){
        if(tl == tr){
            t[v] = max(t[v], x);
            return;
        }
        int mid = (tl + tr) / 2;
        if(mid >= pos) upd(v * 2, tl, mid, pos, x);
        else upd(v * 2 + 1, mid + 1, tr, pos, x);
        t[v] = max(t[v * 2], t[v * 2 + 1]);
    }
    int get(int v, int tl, int tr, int l, int r){
        if(tl > r || l > tr) return 0ll;
        if(tl >= l && r >= tr) return t[v];
        int mid = (tl + tr) / 2;
        return max(get(v * 2, tl, mid, l, r), get(v * 2 + 1, mid + 1, tr, l, r));
    }
};

void solve(){
    cin >> n;
    tree t[n + 1];
    vector<int> v;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
        v.push_back(a[i]);
    }
    for(int i = 1; i <= n; i++){
        cin >> b[i];
        v.push_back(b[i]);
    }
    sort(all(v));
    v.erase(unique(all(v)), v.end());
    for(int i = 1; i <= n; i++){ 
        a[i] = lower_bound(all(v), a[i]) - v.begin() + 1;
        b[i] = lower_bound(all(v), b[i]) - v.begin() + 1; 
    }
    int dp[n + 1][n + 1] = {}, last[n + 1] = {};
    for(int i = 1; i <= n; i++){
        int mx = a[i];
        int cnt[n + 1] = {};
        if(a[i] == b[i]){
            t[i].upd(1, 1, n, i, t[i - 1].get(1, 1, n, 1, i - 1) + 1);
        }
        for(int l = i - 1; l >= 1; l--){
            cnt[b[l]]++;
            mx = max(mx, a[l]);
            // if(mx == a[i]){
            //     t[i].upd(1, 1, n, l, t[i - 1].get(1, 1, n, l, i - 1) + cnt[a[i]]);
            // }
            if(mx == b[i]){
                t[i].upd(1, 1, n, l, t[i - 1].get(1, 1, n, 1, l) + cnt[mx]);
                // t[i].upd(1, 1, n, l, t[i - 1].get(1, 1, n, l, i - 1) + );
            }
            else t[i].upd(1, 1, n, l, t[i - 1].get(1, 1, n, 1, l));
            // cout << t[i - 1].get(1, 1, n, 1, l - 1) + cnt[mx] << ' ' << i << ' ' << l << '\n';
        }
    }
    cout << t[n].get(1, 1, n, 1, n);
}

signed main(){
    SS
    // freopen("trains.in", "r", stdin);
    // freopen("trains.out", "w", stdout);

    int t = 1;
    // cin >> t;
    while(t--){
        solve();
    }
}

• Subtask 1: 0 / 14
• Subtask 2: 0 / 12
• Subtask 3: 0 / 13
• Subtask 4: 0 / 23
• Subtask 5: 0 / 16
• Subtask 6: 0 / 22