Submission #419431

#	Time	Username	Problem	Language	Result	Execution time	Memory
419431		tengiz05	Watching (JOI13_watching)	C++17	100 / 100	816 ms	15300 KiB

watching

#include <bits/stdc++.h>
int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int n, p, q;
    std::cin >> n >> p >> q;
    std::vector<int> a(n);
    for (int i = 0; i < n; i++) {
        std::cin >> a[i];
    }
    if (p + q >= n) {
        std::cout << 1 << "\n";
        return 0;
    }
    sort(a.begin(), a.end());
    auto check = [&](int len) {
        std::vector<std::vector<int>> dp(n + 1, std::vector<int>(q + 1, 1e9));
        dp[0][0] = 0;
        int p1 = 1, p2 = 1;
        for (int i = 1; i <= n; i++) {
            while (a[i - 1] - a[p1 - 1] >= len) p1++;
            while (a[i - 1] - a[p2 - 1] >= 2 * len) p2++;
            for (int Q = 0; Q <= q; Q++) {
                dp[i][Q] = std::min(dp[i][Q], dp[p1 - 1][Q] + 1);
                if (Q) {
                    dp[i][Q] = std::min(dp[i][Q], dp[i][Q - 1]);
                    dp[i][Q] = std::min(dp[i][Q], dp[p2 - 1][Q - 1]);
                }
            }
        }
        return dp[n][q] <= p;
    };
    // for (int i = 1; i <= 17; i++) std::cerr << check(i) << "\n";
    // return 0;
    int l = 0, r = 1000000007;
    while (l + 1 < r) {
        int mid = (l + r) / 2;
        if (check(mid)) {
            r = mid;
        } else {
            l = mid;
        }
    }
    std::cout << r << "\n";
    return 0;
}

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