Submission #1164214

#	Time	Username	Problem	Language	Result	Execution time	Memory
1164214		SmuggingSpun	Radio Towers (IOI22_towers)	C++20	23 / 100	4072 ms	9004 KiB

towers

#include "towers.h"
#include<bits/stdc++.h>
using namespace std;
const int lim = 1e5 + 5;
template<class T>void maximize(T& a, T b){
    if(a < b){
        a = b;
    }
}
int n, k, log_v[lim], h[lim], spt[lim][17];
void init(int N, vector<int>H) {
    n = N;
    log_v[0] = -1;
    for(int i = 0; i < n; i++){
        spt[i + 1][0] = h[i + 1] = H[i];
        log_v[i + 1] = log_v[(i + 1) >> 1] + 1;
    }
    for(int j = 1; j < 17; j++){
        for(int i = 1; i + (1 << j) - 1 <= n; i++){
            spt[i][j] = max(spt[i][j - 1], spt[i + (1 << (j - 1))][j - 1]);
        }
    }
}
int get_max(int l, int r){
    int k = log_v[r - l + 1];
    return max(spt[l][k], spt[r - (1 << k) + 1][k]);
}
int max_towers(int l, int r, int d) {
    l++;
    r++;
    vector<int>dp(n + 1, 0), bit(n + 1, 0);
    auto update = [&] (int p, int x){
        for(; p <= n; p += p & -p){
            maximize(bit[p], x);
        }
    };
    auto get = [&] (int p){
        int ans = 0;
        for(; p > 0; p -= p & -p){
            maximize(ans, bit[p]);
        }
        return ans;
    };
    for(int i = l; i <= r; i++){
        int low = 1, high = i - 1, p = 1;
        while(low <= high){
            int mid = (low + high) >> 1;
            if(get_max(mid, i - 1) - d >= h[i]){
                low = (p = mid) + 1;
            }
            else{
                high = mid - 1;
            }
        }
        dp[i] = get(p) + 1;
        low = i + 1;
        p = (high = n) + 1;
        while(low <= high){
            int mid = (low + high) >> 1;
            if(get_max(i + 1, mid) - d >= h[i]){
                high = (p = mid) - 1;
            }
            else{
                low = mid + 1;
            }
        }
        update(p, dp[i]);
    }
    return *max_element(dp.begin(), dp.end());
}

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