oj.uz

Submission #203739

# Submission time Handle Problem Language Result Execution time Memory
203739 2020-02-22T04:05:39 Z EntityIT Sparklers (JOI17_sparklers) C++14
0 / 100
 5 ms 376 KB 
#include<bits/stdc++.h>

using namespace std;

#define all(x) (x).begin(), (x).end()
#define sz(x) ( (int)(x).size() )
using LL = long long;

template<class T>
inline bool asMn(T &a, const T &b) { return a > b ? a = b, true : false; }
template<class T>
inline bool asMx(T &a, const T &b) { return a < b ? a = b, true : false; }
mt19937 rng( (uint32_t)chrono::steady_clock::now().time_since_epoch().count() );

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

  #ifdef FourLeafClover
  freopen("input", "r", stdin);
  #endif // FourLeafCLover

  int n, k, t; cin >> n >> k >> t; --k;
  vector<int> x(n);
  for (auto &i : x) cin >> i;

  auto check = [&](int s) {
    int l = k, r = k;
    while (l || r ^ (n - 1) ) {
      if (!l) {
        ++r;
        if ( (x[r] - x[l] + t - 1) / t > 2LL * s * (r - l) ) return false;
      }
      else if (!(r ^ (n - 1) ) ) {
        --l;
        if ( (x[r] - x[l] + t - 1) / t > 2LL * s * (r - l) ) return false;
      }
      else {
        if (x[r + 1] - x[r] < x[l] - x[l - 1]) {
          ++r;
          if ( (x[r] - x[l] + t - 1) / t > 2LL * s * (r - l) ) return false;
        }
        else {
          --l;
          if ( (x[r] - x[l] + t - 1) / t > 2LL * s * (r - l) ) return false;
        }
      }
    }
    return true;
  };

  int l = 0, r = x.back();
  while (l < r) {
    int mid = (l + r) >> 1;
    if (check(mid) ) r = mid;
    else l = mid + 1;
  }

  cout << l << '\n';

  return 0;
}

Subtask #1
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 376 KB Output is correct
2 Correct 5 ms 376 KB Output is correct
3 Correct 5 ms 376 KB Output is correct
4 Correct 4 ms 376 KB Output is correct
5 Correct 5 ms 376 KB Output is correct
6 Correct 5 ms 376 KB Output is correct
7 Incorrect 5 ms 376 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 376 KB Output is correct
2 Correct 5 ms 376 KB Output is correct
3 Correct 5 ms 376 KB Output is correct
4 Correct 4 ms 376 KB Output is correct
5 Correct 5 ms 376 KB Output is correct
6 Correct 5 ms 376 KB Output is correct
7 Incorrect 5 ms 376 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #3
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 376 KB Output is correct
2 Correct 5 ms 376 KB Output is correct
3 Correct 5 ms 376 KB Output is correct
4 Correct 4 ms 376 KB Output is correct
5 Correct 5 ms 376 KB Output is correct
6 Correct 5 ms 376 KB Output is correct
7 Incorrect 5 ms 376 KB Output isn't correct
8 Halted 0 ms 0 KB -