Submission #1065830

#	Time	Username	Problem	Language	Result	Execution time	Memory
1065830		j_vdd16	Radio Towers (IOI22_towers)	C++17	14 / 100	681 ms	2040 KiB

towers

#include "towers.h"

#include <algorithm>
#include <bitset>
#include <cstdint>
#include <cstring>
#include <iostream>
#include <limits.h>
#include <math.h>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

//#define int long long
#define loop(X, N) for(int X = 0; X < (N); X++)
#define all(V) V.begin(), V.end()
#define rall(V) V.rbegin(), V.rend()

using namespace std;

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<bool> vb;
typedef vector<vector<bool>> vvb;

typedef uint64_t u64;
typedef int64_t i64;

int n;
vi h;
vi minPref;

int getMax(int l, int r) {
    int best = 0;
    for (int i = l; i <= r; i++) {
        best = max(best, h[i]);
    }

    return best;
}

void init(int N, std::vector<int> H) {
    //all H[i] are different
    //dp[i] = max of 1 and all dp[j] over j s.t. j < i && maxH(j, i) - D >= max(H[i], H[j])

    //D = 1
    //H = 1, 2, 6, 4, 5, 3, 7
    //dp= 1, 1, 1, 2, 2, 3, 1

    n = N;
    h = H;

    if (n == 1) return;

    vb isMinimum(n);
    loop(i, n) {
        if (i == 0) {
            isMinimum[i] = h[i] < h[i + 1];
        }
        else if (i == n - 1) {
            isMinimum[i] = h[i] < h[i - 1];
        }
        else {
            isMinimum[i] = h[i] < h[i + 1] && h[i] < h[i - 1];
        }
    }

    minPref = vi(n + 1);
    for (int i = 1; i < n; i++) {
        minPref[i + 1] = minPref[i] + isMinimum[i];
    }
}

int max_towers(int L, int R, int D) {
    if (L == R) {
        return 1;
    }

    int res = minPref[R] - minPref[L + 1];
    if (L + 1 < n) {
        res += h[L] < h[L + 1];
    }
    else {
        res++;
    }
    if (R - 1 >= 0) {
        res += h[R] < h[R - 1];
    }
    else {
        res++;
    }

    return res;


    // vi dp(n);
    // int res = 0;
    // for (int i = L; i <= R; i++) {
    //     dp[i] = 1;
    //     for (int j = L; j < i; j++) {
    //         if (getMax(j + 1, i - 1) - D >= max(h[i], h[j])) {
    //             dp[i] = max(dp[i], dp[j] + 1);
    //         }
    //     }

    //     res = max(res, dp[i]);
    // }

    // return res;
}

• Subtask 1: 0 / 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