Submission #1067503

#	Time	Username	Problem	Language	Result	Execution time	Memory
1067503		mariaclara	Radio Towers (IOI22_towers)	C++17	18 / 100	658 ms	2792 KiB

towers

#include "towers.h"
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int,int> pii;
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
#define mk make_pair
#define pb push_back
#define fr first
#define sc second

vector<int> val_l, val_r, h, pref;

void init(int N, vector<int> H) {
    val_l.resize(N);
    val_r.resize(N);
    pref.resize(N);
    h = H;

    for(int i = 0; i < N; i++) {
        if(i == 0 or H[i-1] < H[i]) val_l[i] = H[i];
        else val_l[i] = val_l[i-1];
    }

    for(int i = N-1; i >= 0; i--) {
        if(i == N-1 or H[i+1] < H[i]) val_r[i] = H[i];
        else val_r[i] = val_r[i+1];
    }

    for(int i = 1; i < N-1; i++) {
        if(H[i-1] > H[i] and H[i] < H[i+1]) pref[i] = pref[i-1] + 1;
        else pref[i] = pref[i-1];
    }
}

int max_towers(int L, int R, int D) {
    int ans = 0;

    // for(int i = L, last = -1, m = 0; i <= R; i++) {
    //     if(last == -1 or min(m - h[last], m - h[i]) >= D) last = i, ans++, m = 0;
    //     if(h[i] < h[last]) last = i, m = 0;
    //     m = max(m, h[i]);
    // }

    if(val_l[L] == val_l[R] or val_r[L] == val_r[R]) return 1;
    ans = pref[R-1] - pref[L];

    if(val_r[L] - h[L] >= D) ans++;
    if(val_l[R] - h[R] >= D) ans++;

    ans = max(ans, 1);
    return ans;
}

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