Submission #836219

#	Time	Username	Problem	Language	Result	Execution time	Memory
836219		tengiz05	Radio Towers (IOI22_towers)	C++17	0 / 100	4040 ms	2736 KiB

towers

#include "towers.h"

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

vector<int> h;
int n;
void init(int N, vector<int> H) {
    n = N;
    h = H;
}

int max_towers(int l, int r, int D) {
    vector<int> dp(n);
    deque<pair<int, int>> st;
    vector<int> nxt(n, -1);
    for (int i = n - 1; i >= 0; i--) {
        while (!st.empty() && h[st.front().second] <= h[i]) st.pop_front();
        st.push_front({h[i], i});
        auto p = lower_bound(st.begin(), st.end(), pair{h[i] + D, -1});
        if (p != st.end()) {
            nxt[i] = p->second;
        }
    }
    st.clear();
    vector<int> prev(n, -1);
    for (int i = 0; i < n; i++) {
        while (!st.empty() && h[st.front().second] <= h[i]) st.pop_front();
        st.push_front({h[i], i});
        auto p = lower_bound(st.begin(), st.end(), pair{h[i] + D, -1});
        if (p != st.end()) {
            prev[i] = p->second;
        }
    }
    for (int i = l; i <= r; i++) {
        dp[i] = 1;
        for (int j = l; j < i; j++) {
            if (nxt[j] < i && prev[i] > j) {
                dp[i] = max(dp[i], dp[j] + 1);
            }
        }
    }
    return *max_element(dp.begin(), dp.end());
}

• 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