Submission #368020

#	Time	Username	Problem	Language	Result	Execution time	Memory
368020		b23v	Watching (JOI13_watching)	C++14	100 / 100	913 ms	16236 KiB

watching

#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
#include <map>
#include <climits>
#include <cstring>
#include <deque>

using namespace std;

using ll = long long;
using ull = unsigned long long;
using vi = vector<int>;
using ii = pair<int,int>;
using vii = vector<pair<int,int>>;
using vb = vector<bool>;
template<typename T>
using Graph = vector<vector<T>>;

int n, p, q;
vector<ll> A;

int dp[2005][2005];
bool check(ll w)
{
	memset(dp[0], 0x3f, sizeof dp[0]);
	for(int i = 0; i <= p; ++i)
	{
		dp[0][0] = 0;
		int l = 1, r = 1;
		for(int j = 1; j <= n; ++j)
		{
			while(l <= n && A[l] < A[j] - w + 1) ++l;
			while(r <= n && A[r] < A[j] - 2 * w + 1) ++r;

			if(i) dp[i][j] = dp[i - 1][j];

			dp[i][j] = min(dp[i][j], dp[i][r - 1] + 1);
			if(i) dp[i][j] = min(dp[i][j], dp[i - 1][l - 1]);
		}
	}
	return dp[p][n] <= q;
}

void solve()
{
	cin >> n >> p >> q;
	p = min(n, p);
	A.assign(n + 1, 0);
	
	for(int i = 1; i <= n; ++i) cin >> A[i];
	sort(A.begin(), A.end());

	ll ans = -1;
	ll L = 1, R = ll(1e9);
	while(L <= R)
	{
		ll mid = L + (R - L) / 2;
		if(check(mid))
		{
			ans = mid;
			R = mid - 1;
		} else
		{
			L = mid + 1;
		}
	}
	cout << ans << '\n';
}

int main ()
{
#ifdef LOCAL
   freopen("input.txt", "rt", stdin);
   freopen("output.txt", "wt", stdout);
#endif

   	ios_base::sync_with_stdio(false);
	cin.tie(0);
	int tc = 1; 
//	cin >> tc;
	while(tc--) solve();
}

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