Submission #958870

#	Time	Username	Problem	Language	Result	Execution time	Memory
958870		Pring	Watching (JOI13_watching)	C++17	0 / 100	12 ms	31324 KiB

watching

#include <bits/stdc++.h>
using namespace std;

#ifdef MIKU
string dbmc = "\033[1;38;2;57;197;187m", dbrs = "\033[0m";
#define debug(x...) cout << dbmc << "[" << #x << "]: ", dout(x)
void dout() { cout << dbrs << endl; }
template <typename T, typename ...U>
void dout(T t, U ...u) { cout << t << (sizeof...(u) ? ", " : ""); dout(u...); }
#else
#define debug(...) 39
#endif

#define int long long
#define fs first
#define sc second
#define mp make_pair
#define FOR(i, j, k) for (int i = j, Z = k; i < Z; i++)
typedef pair<int, int> pii;

const int MXN = 2005, MXC = 1000000005;
int n, X, Y, a[MXN];
int dp[MXN][MXN], l[MXN], l2[MXN];

void PRE(int w) {
    int p = 0, pp = 0;
    FOR(i, 1, n + 1) {
        while (a[i] - a[p] >= w) p++;
        while (a[i] - a[pp] >= 2 * w) pp++;
        l[i] = p - 1;
        l2[i] = pp - 1;
    }
}

bool check(int w) {
    PRE(w);
    dp[0][0] = 0;
    FOR(i, 1, n + 1) dp[0][i] = dp[0][l2[i]] + 1;
    deque<pii> dq, dq2;
    auto POP = [&](deque<pii> &dq, int t) -> void {
        while (dq.size() && dq.front().fs < t) dq.pop_front();
    };
    auto PUSH = [&](deque<pii> &dq, int id, int val) -> void {
        while (dq.size() && dq.back().sc >= val) dq.pop_back();
        dq.push_back(mp(id, val));
    };
    FOR(j, 1, X + 1) {
        dp[j][0] = 0;
        dq.clear();
        dq2.clear();
        PUSH(dq, 0, dp[j - 1][0]);
        PUSH(dq2, 0, dp[j][0]);
        FOR(i, 1, n + 1) {
            POP(dq, l[i]);
            POP(dq2, l2[i]);
            dp[i][j] = min(dq.front().sc, dq2.front().sc + 1);
            PUSH(dq, i, dp[j - 1][i]);
            PUSH(dq2, i, dp[j][i]);
        }
    }
    // FOR(i, 0, n + 1) {
    //     FOR(j, 0, X + 1) cout << dp[i][j] << ' ';
    //     cout << endl;
    // }
    FOR(j, 0, X + 1) if (dp[j][n] <= Y) return true;
    return false;
    // FOR(i, 0, n + 1) cout << dp[i][0] << '\n';
    // return true;
}

void miku() {
    cin >> n >> X >> Y;
    FOR(i, 1, n + 1) cin >> a[i];
    sort(a + 1, a + n + 1);
    if (X + Y >= n) {
        cout << 1 << '\n';
        return;
    }
    a[0] = -2 * MXC;
    // check(4);
    // return;
    int l = 0, r = MXC;
    while (l + 1 < r) {
        int mid = (l + r) >> 1;
        (check(mid) ? r : l) = mid;
    }
    cout << r << '\n';
}

int32_t main() {
    cin.tie(0) -> sync_with_stdio(false);
    cin.exceptions(cin.failbit);
    miku();
    return 0;
}

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