Submission #1072455

#	Time	Username	Problem	Language	Result	Execution time	Memory
1072455		vjudge1	Radio Towers (IOI22_towers)	C++17	0 / 100	9 ms	2772 KiB

towers

#include "towers.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vll = vector <ll>;
using ii = pair <ll, ll>;
using vii = vector <ii>;
using vi = vector <int>;

ll n, k;
vll ve;
void init (int n, vi ve) {
    ::n = n;
    k = 0;
    ::ve = vll(ve.begin(), ve.end());
    while (ve[k] < ve[k+1]) k++;
}

const ll MAXN = 2E3+16;
ll dp[MAXN];
int max_towers (int ql, int qr, int d) {
    fill(dp+ql, dp+qr+1, 0);
    // cerr << d << '\n';
    for (ll i = ql; i <= qr; i++) {
        ii maxN = { 0, -16 };
        dp[i] = 1;
        for (ll j = i-1; j >= ql; j--) {
            if (ve[i] <= maxN.first-d)
                if (ve[j] <= maxN.first-d) {
                    dp[i] = max(dp[i], dp[j]+1);
                    break;
                }
            maxN = max(maxN, ii{ ve[j], j });
        }
        // cerr << ve[i] << ": " << dp[i] << '\n';
    }
    // return *max_element(dp+ql, dp+qr+1);


    // fill(dp+ql, dp+qr+1, 0);
    // deque <ii> dq;
    // for (ll i = ql; i <= qr; i++) {
    //     dp[i] = 1;
    //     while (dq.size() && dq.front().first < ve[i]) dq.pop_front();
    //     // ll j = lower_bound(dq.begin(), dq.end(), ii{ ve[i]+d, 0 }) - dq.begin();
    //     // j++;
    //     // if (j < dq.size()) dp[i] = max(dp[i], dq[j].second+1);
    //     // cerr << ve[i] << ": " << dp[i] << '\n';
    //     // cerr << "j " << j << "  ";
    //     dq.push_front({ ve[i], dq.size() ? max(dq.front().second, dp[i]) : dp[i] });
    //     for (auto [v1, v2] : dq) cerr << v1 << ' ' << v2 << "  ";
    //     cerr << '\n';
    //     // for (ll j = i-1; j >= ql; j--) {
    //     //     if (ve[i] <= maxN.first-d)
    //     //         if (ve[j] <= maxN.first-d) dp[i] = max(dp[i], dp[j]+1);
    //     //     maxN = max(maxN, ii{ ve[j], j });
    //     // }
    // }
    return *max_element(dp+ql, dp+qr+1);
}

• Subtask 1: 0 / 4
• Subtask 2: 0 / 11
• Subtask 3: 0 / 12
• Subtask 4: 0 / 14
• Subtask 5: 0 / 17
• Subtask 6: 0 / 19
• Subtask 7: 0 / 23