Submission #1274046

#	Time	Username	Problem	Language	Result	Execution time	Memory
1274046		nanaseyuzuki	Watching (JOI13_watching)	C++20	100 / 100	183 ms	16192 KiB

watching

#include <bits/stdc++.h>
// Author: Kazuki_Will_Win_VOI_8703
#define fi first
#define se second
#define pii pair<int, int>
// #define int long long
#define all(a) a.begin(), a.end()
using namespace std;

const int mn = 2e3 + 5, bm = (1 << 11) + 1, mod = 1e9 + 7, offset = 5e4, B = 320 + 5;
const int inf = 1e9, base = 311;

int n, p, q, a[mn], dp[mn][mn], pre[2][mn];

bool check(int mid){
    for(int i = 1; i <= n; i++){
        for(int j = i - 1; j >= 0; j --){
            if(a[i] - a[j] >= mid || j == 0){
                pre[0][i] = j;
                break;
            }
        }
    }

    for(int i = 1; i <= n; i++){
        for(int j = i - 1; j >= 0; j --){
            if(a[i] - a[j] >= 2 * mid || j == 0){
                pre[1][i] = j;
                break;
            }
        }
    }

    fill(&dp[0][0], &dp[0][0] + mn * mn, inf);
    dp[0][0] = 0;

    for(int i = 1; i <= n; i++){
        for(int j = 0; j <= min(n, q); j++){
            dp[i][j] = min(dp[i][j], dp[pre[0][i]][j] + 1);
            if(j > 0) dp[i][j] = min(dp[pre[1][i]][j - 1], dp[i][j]);
        }
    }
    for(int i = 0; i <= min(n, q); i++) if(dp[n][i] <= p) return true;
    return false;
}

void solve(){
    cin >> n >> p >> q;
    for(int i = 1; i <= n; i++) cin >> a[i];
    sort(a + 1, a + n + 1);
    int l = 1, r = 1e9, ans = -1;
    while(l <= r){
        int mid = (l + r) >> 1;
        if(check(mid)){
            ans = mid;
            r = mid - 1;
        }
        else l = mid + 1;
    }
    cout << ans << '\n';
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int t = 1;
    // cin >> t;
    while(t--){
        solve();
    }
}

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