Submission #601343

#	Time	Username	Problem	Language	Result	Execution time	Memory
601343		elkernos	Watching (JOI13_watching)	C++17	100 / 100	344 ms	15440 KiB

watching

#include <bits/stdc++.h>

using namespace std;

int32_t main()
{
    cin.tie(0)->sync_with_stdio(0);
    int n, p, q;
    cin >> n >> p >> q;
    vector<int> a(n + 1);
    for(int i = 1; i <= n; ++i) {
        cin >> a[i];
    }
    sort(1 + a.begin(), a.end());
    auto good = [&](int x) {
        int one = 1, two = 1;
        vector<vector<int>> dp(n + 1, vector<int>(q + 1));
        for(int i = 1; i <= n; ++i) {
            while(a[i] - a[one] >= x) {
                ++one;
            }
            while(a[i] - a[two] >= x * 2) {
                ++two;
            }
            for(int j = 0; j <= q; ++j) {
                dp[i][j] = dp[one - 1][j] + 1;
            }
            for(int j = 0; j < q; ++j) {
                if(dp[i][j + 1] > dp[two - 1][j]) {
                    dp[i][j + 1] = dp[two - 1][j];
                }
            }
        }
        return (dp[n][q] <= p);
    };
    if(n <= p + q) {
        cout << 1 << '\n';
        exit(0);
    }
    int l = 1, r = 1000000000, ans = -1;
    while(l <= r) {
        int m = (l + r) / 2;
        if(good(m)) {
            r = m - 1;
            ans = m;
        }
        else {
            l = m + 1;
        }
    }
    cout << ans << '\n';
}

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