Submission #660046

#	Time	Username	Problem	Language	Result	Execution time	Memory
660046		Radin_Zahedi2	The short shank; Redemption (BOI21_prison)	C++17	0 / 100	26 ms	47220 KiB

prison

#include<bits/stdc++.h>
//#pragma GCC optimize("O2")
using namespace std;
using ll = long long;
using ld = long double;
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define sz(x) (int)x.size()
#define endl '\n'
const int mod = 1e9 + 7;
const int inf = 2e9 + 5;
const ll linf = 9e18 + 5;


int n, d, t;
const int N = 2e6 + 5;
int arr[N];

int all = 0;
vector<int> adj[N];
int depth[N];
vector<int> have;

void init() {
}

void input() {
	cin >> n >> d >> t;

	for (int i = 1; i <= n; i++) {
		cin >> arr[i];
	}
}

void creadj() {
	vector<int> have;

	bool can[n + 1];
	int ends[n + 1];
	fill(ends + 1, ends + n + 1, 0);

	all = 1;
	for (int i = 1; i <= n; i++) {
		while (!have.empty()) {
			int ind = have.back();
			if (arr[ind] - ind < arr[i] - i) {
				break;
			}
			have.pop_back();
		}
		have.pb(i);

		if (arr[have[0]] - have[0] <= t - i) {
			int l = 0, r = sz(have);

			while (l + 1 != r) {
				int m = (l + r) / 2;

				if (arr[have[m]] - have[m] <= t - i) {
					l = m;
				}
				else {
					r = m;
				}
			}

			all++;
			if (have[l] != i) {
				ends[have[l]]++;
				can[i] = true;
			}
			else {
				can[i] = false;
			}
		}
		else {
			can[i] = false;
		}
	}


	stack<int> verts;
	verts.push(0);
	for (int i = n; i >= 1; i--) {
		if (!can[i]) {
			continue;
		}

		adj[verts.top()].pb(i);

		verts.push(i);
		for (int j = 0; j < ends[i]; j++) {
			verts.pop();
		}
	}
}

void dfsdepth(int u) {
	for (auto v : adj[u]) {
		dfsdepth(v);
		depth[u] = max(depth[u], depth[v] + 1);
	}

	for (int i = 0; i < sz(adj[u]); i++) {
		if (depth[adj[u][0]] < depth[adj[u][i]]) {
			swap(adj[u][0], adj[u][i]);
		}
	}
}

void dfs(int u, int d) {
	if (adj[u].empty()) {
		have.pb(d);
		return;
	}
	
	dfs(adj[u][0], d + 1);
	for (auto v : adj[u]) {
		if (v != adj[u][0]) {
			dfs(v, 1);
		}
	}
}

void solve() {
	creadj();
	dfsdepth(0);
	dfs(0, 1);

	sort(have.begin(), have.end());
	reverse(have.begin(), have.end());
	for (int i = 0; i < d && i < sz(have); i++) {
		all -= have[i];
	}

	cout << all;
}

void output() {
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);

	int number_of_testcases = 1;
	//cin >> number_of_testcases;
	while (number_of_testcases--) {
		init();

		input();

		solve();

		output();
	}

	return 0;
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 10
• Subtask 3: 0 / 20
• Subtask 4: 0 / 10
• Subtask 5: 0 / 25
• Subtask 6: 0 / 20