Submission #798815

#	Time	Username	Problem	Language	Result	Execution time	Memory
798815		arush_agu	Watching (JOI13_watching)	C++17	100 / 100	429 ms	30348 KiB

watching

#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#ifdef DEBUG
#include <time.h>
#endif

#define all(a) (a).begin(), (a).end()
#define rev(a) (a).rbegin(), (a).rend()
#define F first
#define S second
int recur_depth = 0;
#ifdef DEBUG
#define dbg(x)                                                                 \
  {                                                                            \
    ++recur_depth;                                                             \
    auto x_ = x;                                                               \
    --recur_depth;                                                             \
    cerr << string(recur_depth, '\t') << "\e[91m" << __func__ << ":"           \
         << __LINE__ << "\t" << #x << " = " << x_ << "\e[39m" << endl;         \
  }
#else
#define dbg(x)
#endif

using namespace std;
using namespace __gnu_pbds;

typedef pair<int, int> ii;

typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> llll;

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pair<int, int>> vii;
typedef vector<vii> vvii;

typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<pair<ll, ll>> vll;
typedef vector<vll> vvll;

typedef vector<bool> vb;

template <class type1>
using ordered_set = tree<type1, null_type, less<type1>, rb_tree_tag,
                         tree_order_statistics_node_update>;

template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p) {
  return os << '(' << p.first << ", " << p.second << ')';
}
template <typename T_container, typename T = typename enable_if<
                                    !is_same<T_container, string>::value,
                                    typename T_container::value_type>::type>
ostream &operator<<(ostream &os, const T_container &v) {
  os << '{';
  string sep;
  for (const T &x : v)
    os << sep << x, sep = ", ";
  return os << '}';
}

const ll MOD = 1e9 + 7;
// const ll MOD = 998244353;
const ll INF = 1e18;
const ld EPS = 1e-9;

void solve() {
  int n, p, q;
  cin >> n >> p >> q;
  vl a(n);
  for (ll &x : a)
    cin >> x;

  if (p + q >= n) {
    cout << "1\n";
    return;
  }

  sort(all(a));

  auto check = [&](ll w) -> bool {
    vi cw(n), cw2(n);
    int w_idx = 0, w2_idx = 0;
    for (int i = 0; i < n; i++) {
      while (a[w_idx] <= a[i] - w)
        w_idx++;
      while (a[w2_idx] <= a[i] - w - w)
        w2_idx++;

      cw[i] = w_idx, cw2[i] = w2_idx;
    }

    vvl dp(n + 1, vl(q + 1));
    for (int i = 1; i <= n; i++) {
      int idx = i - 1;
      dp[i][0] = dp[cw[idx]][0] + 1;
      for (int qq = 1; qq <= q; qq++) {
        dp[i][qq] = min(dp[cw2[idx]][qq - 1], dp[cw[idx]][qq] + 1);
      }

      if (dp[i][q] > p)
        return 0;
    }

    return dp[n][q] <= p;
  };

  int l = 1, r = 1e9, ans = 1e9;
  while (l <= r) {
    int mid = (l + r) / 2;
    if (check(mid)) {
      r = mid - 1;
      ans = mid;
    } else
      l = mid + 1;
  }

  cout << ans << "\n";
}

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

  clock_t start = clock();

  int test_cases = 1;
  // cin >> test_cases;

  while (test_cases--)
    solve();

#ifdef DEBUG
  cerr << fixed << setprecision(10)
       << "\nTime Taken: " << (double)(clock() - start) / CLOCKS_PER_SEC
       << "s\n";
#endif
  return 0;
}

Compilation message (stderr)

watching.cpp: In function 'int main()':
watching.cpp:150:11: warning: unused variable 'start' [-Wunused-variable]
  150 |   clock_t start = clock();
      |           ^~~~~

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