Submission #550839

#	Time	Username	Problem	Language	Result	Execution time	Memory
550839		Soumya1	Watching (JOI13_watching)	C++17	100 / 100	422 ms	23852 KiB

watching

#include <bits/stdc++.h>
#ifdef __LOCAL__
#include <debug_local.h>
#endif
using namespace std;
const int mxN = 3000;
int dp[mxN][mxN];
int a[mxN];
int to[mxN], to1[mxN];
void testCase() {
  int n, p, q;
  cin >> n >> p >> q;
  p = min(p, n + 50);
  q = min(q, n + 50);
  for (int i = 1; i <= n; i++) cin >> a[i];
  sort(a, a + n + 1);
  auto check = [&](int w) {
    for (int i = 0; i <= n; i++) {
      for (int j = 0; j <= p; j++) {
        dp[i][j] = q + 1;
        if (i == 0) dp[i][j] = 0;
      }
    }
    for (int i = 1; i <= n; i++) {
      to[i] = lower_bound(a, a + n + 1, a[i] - w + 1) - a - 1;
      to1[i] = lower_bound(a, a + n + 1, a[i] - 2 * w + 1) - a - 1;
      to[i] = max(0, to[i]);
      to1[i] = max(0, to1[i]);
    }
    for (int i = 1; i <= n; i++) {
      for (int j = 0; j <= p; j++) {
        if (j) dp[i][j] = dp[to[i]][j - 1];
        if (dp[to1[i]][j] < q) dp[i][j] = min(dp[i][j], dp[to1[i]][j] + 1);
      }
    }
    return (*min_element(dp[n], dp[n] + p + 1) <= q);
  };
  int lo = 1, hi = 1e9;
  while (lo < hi) {
    int mid = (lo + hi) >> 1;
    if (check(mid)) hi = mid;
    else lo = mid + 1;
  }
  cout << lo << "\n";
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  testCase();
  return 0;
}

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