Submission #1070413

#	Time	Username	Problem	Language	Result	Execution time	Memory
1070413		juicy	Exam (eJOI20_exam)	C++17	12 / 100	15 ms	3160 KiB

exam

#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif

int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);

    int n; cin >> n;
    vector<int> a(n), b(n);
    for (int &x : a) {
        cin >> x;
    }
    for (int &x : b) {
        cin >> x;
    }
    if (n > 5000) {
        int res = 0;
        for (int i = 0; i < n; ++i) {
            if (a[i] > b[0]) {
                continue;
            }
            int j = i - 1;
            bool flg = 0;
            while (j + 1 < n && a[j + 1] <= b[0]) {
                flg |= a[++j] == b[0];
            }
            res += flg * (j - i + 1);
            i = j;
        }
        cout << res;
        exit(0);
    }
    vector<int> comp;
    for (int i = 0; i < n; ++i) {
        comp.push_back(a[i]);
        comp.push_back(b[i]);
    }
    sort(comp.begin(), comp.end());
    comp.erase(unique(comp.begin(), comp.end()), comp.end());
    for (int i = 0; i < n; ++i) {
        a[i] = lower_bound(comp.begin(), comp.end(), a[i]) - comp.begin();
        b[i] = lower_bound(comp.begin(), comp.end(), b[i]) - comp.begin();
    }
    int m = comp.size();
    vector<int> dp(n + 1), cnt(m);
    dp[0] = 0;
    for (int i = 1; i <= n; ++i) {
        dp[i] = dp[i - 1];
        int ma = 0;
        for (int j = i - 1; j >= 0; --j) {
            ma = max(ma, a[j]);
            ++cnt[b[j]];
            dp[i] = max(dp[i], dp[j] + cnt[ma]);
        }
        for (int j = 0; j < i; ++j) {
            cnt[b[j]] = 0;
        }
    }
    cout << dp.back();
    return 0;
}

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