Submission #1261868

#	Time	Username	Problem	Language	Result	Execution time	Memory
1261868		reginox	Watching (JOI13_watching)	C++20	0 / 100	24 ms	15944 KiB

watching

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define all(v) begin(v), end(v)
#define pi pair<int, int>
#define vi vector<int>
using namespace std;
const int N = 2e3+3;
int n, p, q, a[N];
int dp[N][N];

bool ck(int d){
  memset(dp, 0, sizeof(dp));
  dp[1][0] = lower_bound(a+1, a+n+1, a[1] + d) - a - 1;
  dp[0][1] = lower_bound(a+1, a+n+1, a[1] + 2*d) - a - 1;
  // cout << d << "\n";
  for(int i = 1; i <= p; i++){
    for(int j = 1; j <= q; j++){
        int ff = lower_bound(a+1, a+n+1, a[dp[i-1][j] + 1] + d) - a - 1;
        dp[i][j] = max(dp[i][j], ff);
        ff = lower_bound(a+1, a+n+1, a[dp[i][j-1] + 1] + 2*d) - a - 1;
        dp[i][j] = max(dp[i][j], ff);
        // cout << dp[i][j] << " ";
    } 
    // cout << '\n';
  }
  return dp[p][q] >= n;
}

int main(){
  ios_base::sync_with_stdio(0); cin.tie(0);
  cin >> n >> p >> q;
  if(p + q >= n){
    cout << 1;
    return 0;
  }
  p = min(p, n), q = min(q, n);
  for(int i = 1; i <= n; i++) cin >> a[i];
  a[n+1] = a[n];
  sort(a+1, a+n+1);
  int ans, L = 1, R = 1e9, mid;
  while(L <= R){
    mid = (L+R)/2;
    if(ck(mid)){
      ans = mid;
      R = mid - 1;
    }
    else L = mid + 1;
  }
  cout << ans;
  return 0;
}

• Subtask 1: 0 / 50
• Subtask 2: 0 / 50