Submission #469197

#	Time	Username	Problem	Language	Result	Execution time	Memory
469197		Return_0	Watching (JOI13_watching)	C++17	100 / 100	203 ms	16060 KiB

watching

#pragma GCC optimize("Ofast,unroll-loops")
// #pragma comment(linker, "/stack:200000000")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma,tune=native")

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

typedef int ll;
typedef long double ld;
typedef pair <ll, ll> pll;

#ifdef SINA
#define dbg(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1> void __f(const char* name, Arg1&& arg1) { cout << name << " : " << arg1 << std::endl; }
template <typename Arg1, typename... Args> void __f (const char* names, Arg1&& arg1, Args&&... args) {
	const char* comma = strchr(names + 1, ',');cout.write(names, comma - names) << " : " << arg1<<" | ";__f(comma+1, args...); }
#define dbg2(x, j, n) cout<< #x << " : "; output((j), (n), x, 1); cout.flush();
#else
#define dbg(...) 0
#define dbg2(x, j, n) 0
#endif
#define SZ(x) ((ll)((x).size()))
#define File(s, t) freopen(s ".txt", "r", stdin); freopen(t ".txt", "w", stdout);
#define input(j, n, a) for (int _i = (j); _i < (n)+(j); _i++) cin>> a[_i];
#define output(j, n, a, t) for (int _i = (j); _i < (n)+(j); _i++) cout<< a[_i] << (((t) && _i != (n)+(j)-1)? ' ' : '\n');
#define kill(x) return cout<< (x) << endl, 0
#define cl const ll
#define fr first
#define sc second
#define lc (v << 1)
#define rc (lc | 1)
#define mid ((l + r) >> 1)
#define All(x) (x).begin(), (x).end()

cl inf = sizeof(ll) == 4 ? (1e9 + 10) : (3e18), mod = 1e9 + 7, MOD = 998244353;

template <class A,class B> ostream& operator << (ostream& out,const pair<A,B>&a){return out<<'('<<a.first<<", "<<a.second<<')';}
template <class A> ostream& operator << (ostream& out, const vector<A> &a) {
	out<< '['; for (int i = -1; ++i < int(a.size());) out<< a[i] << (i + 1 < int(a.size()) ? ", " : ""); return out<<']'; }
template <class T, typename _t = less <T> > using Tree = tree <T, null_type, _t, rb_tree_tag, tree_order_statistics_node_update>;

cl N = 2e3 + 7;

ll a [N], L [N][2], dp [N][N], n, A, B;

bool check (cl & w) {
	for (ll i = 2; i <= n; i++) {
		for (L[i][0] = L[i - 1][0]; a[i] - a[L[i][0]] >= w; L[i][0]++);
		for (L[i][1] = L[i - 1][1]; a[i] - a[L[i][1]] >= w << 1; L[i][1]++);
	}
	for (ll i = 1; i <= n; i++) for (ll j = 0; j <= A; j++) {
		dp[i][j] = inf;
		if (j) dp[i][j] = dp[L[i][0] - 1][j - 1];
		dp[i][j] = min(dp[i][j], dp[L[i][1] - 1][j] + 1);
	}
	return (dp[n][A] <= B);
}

int main ()
{
	cin.tie(0)->sync_with_stdio(false);

	cin>> n >> A >> B;
	if (n <= A + B) kill(1);
	input(1, n, a);
	sort(a + 1, a + n + 1);
	ll l = 0, r = inf;
	L[1][0] = L[1][1] = 1;
	while (r - l > 1) {
		if (check(mid)) r = mid;
		else l = mid;
	}
	cout<< (r == inf ? -1 : r) << endl;

	cerr<< "\n" __TIMESTAMP__ " - Time elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";

	return 0;
}
/*
3 1 1
2
11
17

*/

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