Submission #825347

#	Time	Username	Problem	Language	Result	Execution time	Memory
825347		Nelt	Watching (JOI13_watching)	C++17	100 / 100	154 ms	30100 KiB

watching

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,avx2,fma")

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

/* DEFINES */
#define S second
#define F first
#define ll long long
#define ull unsigned long long
#define ld long double
#define npos ULLONG_MAX
#define INF LLONG_MAX
#define vv(a) vector<a>
#define pp(a, b) pair<a, b>
#define pq(a) priority_queue<a>
#define qq(a) queue<a>
#define ss(a) set<a>
#define mm(a, b) map<a, b>
#define ump(a, b) unordered_map<a, b>
#define ANDROID                   \
    ios_base::sync_with_stdio(0); \
    cin.tie(0);                   \
    cout.tie(0);
#define elif else if
#define endl "\n"
#define allc(a) begin(a), end(a)
#define all(a) a, a + sizeof(a) / sizeof(a[0])
#define pb push_back
#define logi(a) __lg(a)
#define sqrt(a) sqrtl(a)
#define mpr make_pair
#define ins insert
using namespace std;
using namespace __gnu_pbds;
using namespace __cxx11;
typedef char chr;
typedef basic_string<chr> str;
template <typename T, typename key = less<T>>
using ordered_set = tree<T, null_type, key, rb_tree_tag, tree_order_statistics_node_update>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void solve()
{
    ll n, p, q;
    cin >> n >> p >> q;
    ll a[n + 1];
    for (ll i = 1; i <= n; i++)
        cin >> a[i];
    if (p + q >= n)
    {
        cout << "1\n";
        return;
    }
    sort(a + 1, a + n + 1);
    ll l = 1, r = 1e9, ans = 1e9, dp[n + 1][p + 1];
    while (l <= r)
    {
        ll mid = (l + r) >> 1, res = q + 1, pos, pos1;
        for (ll i = 0; i <= n; i++)
            for (ll j = 0; j <= p; j++)
                dp[i][j] = 0;
        for (ll i = 1; i <= n; i++)
        {
            pos = upper_bound(a + 1, a + n + 1, a[i] - mid) - a - 1;
            pos1 = upper_bound(a + 1, a + n + 1, a[i] - (mid << 1)) - a - 1;
            for (ll j = 0; j <= p; j++)
                dp[i][j] = min(j ? dp[pos][j - 1] : q + 1, dp[pos1][j] + 1);
        }
        for (ll i = 0; i <= p; i++)
            res = min(res, dp[n][i]);
        if (res <= q)
            r = mid - 1, ans = mid;
        else
            l = mid + 1;
    }
    cout << ans << endl;
}

/*

*/
int main()
{
    ANDROID
    // precomp();
    ll t = 1;
    // cin >> t;
    for (ll i = 1; i <= t; i++)
        // cout << "Case #" << i << ": ",
        solve();
    cerr << "\nTime elapsed : " << clock() * 1000.0 / CLOCKS_PER_SEC << " ms\n";
}

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