Submission #947222

#	Time	Username	Problem	Language	Result	Execution time	Memory
947222		Nhoksocqt1	Radio Towers (IOI22_towers)	C++17	15 / 100	4056 ms	1624 KiB

towers

#ifndef Nhoksocqt1
    #include "towers.h"
#endif // Nhoksocqt1
#include<bits/stdc++.h>
using namespace std;

#define inf 0x3f3f3f3f
#define sz(x) int((x).size())
#define fi first
#define se second
typedef long long ll;
typedef pair<int, int> ii;

template<class X, class Y>
	inline bool maximize(X &x, const Y &y) {return (x < y ? x = y, 1 : 0);}
template<class X, class Y>
	inline bool minimize(X &x, const Y &y) {return (x > y ? x = y, 1 : 0);}

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int Random(int l, int r) {
    return uniform_int_distribution<int>(l, r)(rng);
}

const int MAXN = 100005;

int dp[MAXN];
int h[MAXN], nArr, ksub1;
bool check_sub1;

void init(int _N, vector<int> _H) {
    nArr = _N;
    ksub1 = 1;
    for (int i = 1; i <= nArr; ++i) {
        h[i] = _H[i - 1];
        if(h[ksub1] < h[i])
            ksub1 = i;
    }

    check_sub1 = 1;
    for (int i = 3; i <= nArr; ++i)
        check_sub1 &= (h[i - 2] < h[i - 1] || h[i - 1] > h[i]);
}

int max_towers(int l, int r, int d) {
    ++l, ++r;
    if(check_sub1) {
        int res = 1 + (l < ksub1 && ksub1 < r && max(h[l], h[r]) <= h[ksub1] - d);
        return res;
    }

    for (int i = l; i <= r; ++i)
        dp[i] = 1;

    for (int i = l; i <= r; ++i) {
        int k(i + 1);
        for (int j = i + 2; j <= r; ++j) {
            if(h[k] - d >= max(h[i], h[j]))
                dp[j] = max(dp[j], dp[i] + 1);

            if(h[j] > h[k])
                k = j;
        }
    }

    int res(0);
    for (int i = l; i <= r; ++i)
        res = max(res, dp[i]);

    return res;
}

#ifdef Nhoksocqt1

int main(void) {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);

    #define TASK "towers"
    if(fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }

    vector<int> _H;
    int _N, _Q;
    cin >> _N;

    _H.resize(_N);
    for (int i = 0; i < _N; ++i)
        cin >> _H[i];

    init(_N, _H);

    cin >> _Q;
    for (int t = 0; t < _Q; ++t) {
        int _L, _R, _D;
        cin >> _L >> _R >> _D;
        cout << "ANSWER FOR " << _L + 1 << ' ' << _R + 1 << ' ' << _D << ": " << max_towers(_L, _R, _D) << '\n';
    }

    return 0;
}

#endif // Nhoksocqt1

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