Submission #462105

#	Time	Username	Problem	Language	Result	Execution time	Memory
462105		nickyrio	Watching (JOI13_watching)	C++17	100 / 100	333 ms	16196 KiB

watching

#include <bits/stdc++.h>

using namespace std;

void Min(int &a, int b) { a = (a > b ? b : a); }
const int N = 2020;

int n, p, q, a[N];
int dp[N][N];

bool Check(long long w) {
    for (int i = 0; i <= n; ++i) {
        for (int j = 0; j <= p; ++j) dp[i][j] = 1e9;
    }
    dp[0][0] = 0;
    for (int i = 0; i < n; ++i) {
        int nxt_p = lower_bound(a, a + n, a[i] + w) - a;
        int nxt_q = lower_bound(a, a + n, a[i] + w + w) - a;
        for (int np = 0; np <= p; ++np) {
            Min(dp[nxt_p][np + 1], dp[i][np]);
            Min(dp[nxt_q][np], dp[i][np] + 1);
        }
    }
    for (int i = 0; i <= p; ++i) if (dp[n][i] <= q) return true;
    return false;
}
int main() {
    ios::sync_with_stdio(false); cin.tie(NULL);
    cin >> n >> p >> q;
    p = min(p, n), q = min(q, n);
    for (int i = 0; i < n; ++i) cin >> a[i];
    sort(a, a + n);
    int l = 0, r = 1e9, cur = -1;
    while (l <= r) {
        int mid = (l + r) >> 1;
        if (Check(mid)) {
            cur = mid;
            r = mid - 1;
        } else l = mid + 1;
    }
    cout << cur << '\n';
}

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