Submission #1174234

#	Time	Username	Problem	Language	Result	Execution time	Memory
1174234		nguyenkhangninh99	Watching (JOI13_watching)	C++17	100 / 100	121 ms	16164 KiB

watching

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

const int maxn = 2e3 + 5;
int a[maxn], dp[maxn][maxn], prep[maxn], preq[maxn];

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int n, p, q; cin >> n >> p >> q;
    for (int i = 1; i <= n; i++) cin >> a[i];
    sort(a + 1, a + 1 + n);

    if (n <= p + q) cout << 1;
    else{
        int ans = 0;
        for (int bit = 29; bit >= 0; bit--) {
            int cur = ans | (1 << bit), pp = 0, pq = 0;
            for(int i = 1; i <= n; i++){
                while(pp + 1 <= n && a[i] - a[pp + 1] >= cur) pp++;
                while(pq + 1 <= n && a[i] - a[pq + 1] >= 2 * cur) pq++;
                prep[i] = pp;
                preq[i] = pq;
            }

            for (int i = 1; i <= n; i++){
                for (int j = 0; j <= q; j++){
                    dp[i][j] = dp[prep[i]][j] + 1;
                    if(j) dp[i][j] = min(dp[i][j], dp[preq[i]][j - 1]);
                }
            }

            if(dp[n][q] > p) ans = cur;
        }

        cout << ans + 1;
    }
}

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