Submission #464319

#	Time	Username	Problem	Language	Result	Execution time	Memory
464319		Hamed5001	Watching (JOI13_watching)	C++14	0 / 100	4 ms	332 KiB

watching

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

const int mxN = 2e3+10;
int A[mxN], N, P, Q;

bool ok(ll mid) {
	priority_queue<pair<int, int>> pq;
	vector<int> cameraFreq(N+10, 0);
	for (int i = 0; i < N; i++) {
		int can = lower_bound(A+i, A+N, A[i] + mid*2) - (A+i);
		// cerr << i << ' ' << can << ' ' << mid << endl;
		pq.push({can, i});
	} 
	int PP = P, QQ = Q;
	while(QQ && !pq.empty()) {
		cameraFreq[pq.top().second]++;
		cameraFreq[pq.top().second+pq.top().first]--;
		// cout << pq.top().first << ' ' << pq.top().second << ' ' << mid << endl;
		pq.pop();
		QQ--;
	}
	for (int i = 1; i <= N+1; i++)
		cameraFreq[i] += cameraFreq[i-1];
	PP += QQ;
	// cerr << PP << endl;
	for (int i = 0; i < N; i++) {
		if (!cameraFreq[i]) {
			PP--;
			i = lower_bound(A+i, A+N, A[i] + mid) - A - 1;
		}
	}
	// cerr << PP << endl;
	return PP >= 0;
}

void solve() {
	cin >> N >> P >> Q;
	for (int i = 0; i < N; i++)
		cin >> A[i];

	sort(A, A+N);

	ll l = 1, r = 1e10, mid;
	while(l < r) {
		mid = (l+r) >> 1;
		if (ok(mid)) r = mid;
		else l = mid+1;
	}
	cout << r << endl;
}

int main() {

	ios_base::sync_with_stdio(false);
	cin.tie(0);
	solve();
}

• Subtask 1: 0 / 50
• Subtask 2: 0 / 50