Submission #828146

#	Time	Username	Problem	Language	Result	Execution time	Memory
828146		arush_agu	Collecting Stamps 3 (JOI20_ho_t3)	C++17	0 / 100	1 ms	444 KiB

ho_t3

#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;

// Saw solution

void solve() {
  ll n, l;
  cin >> n >> l;
  vll ls(n);
  for (auto &[x, _] : ls)
    cin >> x;
  for (auto &[_, x] : ls)
    cin >> x;
  vll rs = ls;
  ls.push_back({0, 0});
  sort(all(ls));
  rs.push_back({l, 0});
  sort(rev(rs));

  auto dist = [&](ll x, ll y) {
    if (x > y)
      swap(x, y);
    return min(y - x, l - (y - x));
  };

  int ans = 0;
  vector<vector<vvl>> dp(n + 1, vector<vvl>(n + 1, vvl(n + 1, vl(2, INF))));
  for (int left = 1; left <= n; left++)
    if (dist(0, ls[left].first) <= ls[left].second) {
      dp[left][0][1][0] = dist(0, ls[left].first);
      dp[left][0][1][1] = 2 * dist(0, ls[left].first);
    }
  for (int right = 1; right <= n; right++)
    if (dist(0, rs[right].first) <= rs[right].second) {
      dp[0][right][1][1] = dist(0, rs[right].first);
      dp[0][right][1][0] = 2 * dist(0, rs[right].first);
    }

  for (int cnt = 1; cnt <= n; cnt++)
    for (int left = 0; left <= n; left++)
      for (int right = 0; right + left <= n; right++) {
        if (left > 0) {
          dp[left][right][cnt][0] =
              min({dp[left][right][cnt][0],
                   dp[left - 1][right][cnt][0] +
                       dist(ls[left - 1].first, ls[left].first),
                   dp[left - 1][right][cnt][1] +
                       dist(rs[right].first, ls[left].first)});
          if (dp[left - 1][right][cnt - 1][0] +
                  dist(ls[left - 1].first, ls[left].first) <=
              ls[left].second) {
            dp[left][right][cnt][0] =
                min(dp[left][right][cnt][0],
                    dp[left - 1][right][cnt - 1][0] +
                        dist(ls[left - 1].first, ls[left].first));
          }

          if (dp[left - 1][right][cnt - 1][1] +
                  dist(rs[right].first, ls[left].first) <=
              ls[left].second) {
            dp[left][right][cnt][0] =
                min(dp[left][right][cnt][0],
                    dp[left - 1][right][cnt - 1][1] +
                        dist(rs[right].first, ls[left].first));
          }
        }

        if (right > 0) {
          dp[left][right][cnt][1] =
              min({dp[left][right][cnt][1],
                   dp[left][right - 1][cnt][1] +
                       dist(rs[right].first, rs[right - 1].second),
                   dp[left][right - 1][cnt][0] +
                       dist(ls[left].first, rs[right].first)});
          if (dp[left][right - 1][cnt - 1][1] +
                  dist(rs[right - 1].first, rs[right].first) <=
              rs[right].second) {
            dp[left][right][cnt][1] =
                min(dp[left][right][cnt][1],
                    dp[left][right - 1][cnt - 1][1] +
                        dist(rs[right - 1].first, rs[right].first));
          }

          if (dp[left][right - 1][cnt - 1][0] +
                  dist(ls[left].first, rs[right].first) <=
              rs[right].second) {
            dp[left][right][cnt][1] =
                min(dp[left][right][cnt][1],
                    dp[left][right - 1][cnt - 1][0] +
                        dist(ls[left].first, rs[right].first));
          }
        }

        if (dp[left][right][cnt][0] < INF || dp[left][right][cnt][1] < INF)
          ans = cnt;
      }

  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)

ho_t3.cpp: In function 'int main()':
ho_t3.cpp:193:11: warning: unused variable 'start' [-Wunused-variable]
  193 |   clock_t start = clock();
      |           ^~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 75