제출 #392636

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
392636		usachevd0	Shortcut (IOI16_shortcut)	C++14	38 / 100	2091 ms	141632 KiB

shortcut

#include <bits/stdc++.h>
#ifndef DEBUG
  #include "shortcut.h"
#endif

using namespace std;

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define all(a) (a).begin(), (a).end()
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
using ld = long double;
template<typename T1, typename T2> bool chkmin(T1& x, T2 y) {
  return y < x ? (x = y, true) : false;
}
template<typename T1, typename T2> bool chkmax(T1& x, T2 y) {
  return y > x ? (x = y, true) : false;
}
void debug_out() {
  cerr << endl;
}
template<typename T1, typename... T2> void debug_out(T1 A, T2... B) {
  cerr << ' ' << A;
  debug_out(B...);
}
template<typename T> void mdebug_out(T* a, int n) {
  for (int i = 0; i < n; ++i) {
    cerr << a[i] << ' ';
  }
  cerr << endl;
}
#ifdef DEBUG
  #define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
  #define mdebug(a, n) cerr << #a << ": ", mdebug_out(a, n)
#else
  #define debug(...) 1337
  #define mdebug(a, n) 1337
#endif
template<typename T> ostream& operator << (ostream& stream, const vector<T>& v) {
  for (auto& x : v) {
    stream << x << ' ';
  }
  return stream;
}
template<typename T1, typename T2> ostream& operator << (ostream& stream, const pair<T1, T2>& p) {
  return stream << p.first << ' ' << p.second;
}


const ll inf64 = 1e18;

ll find_shortcut(int n, vector<int> dx, vector<int> d, int c) {
  vector<ll> x(n);
  for (int i = 0; i + 1 < n; ++i) {
    x[i + 1] = x[i] + dx[i];
  }
  vector<ll> prf_p(n, -inf64);
  for (int i = 1; i < n; ++i) {
    prf_p[i] = prf_p[i - 1];
    for (int j = i - 1; j >= 0; --j) {
      chkmax(prf_p[i], d[j] + x[i] - x[j] + d[i]);
    }
  }
  vector<ll> suf_p(n + 1, -inf64);
  for (int i = n - 2; i >= 0; --i) {
    suf_p[i] = suf_p[i + 1];
    for (int j = i + 1; j < n; ++j) {
      chkmax(suf_p[i], d[i] + x[j] - x[i] + d[j]);
    }
  }

  vector<ll> v[2];
  vector<vector<ll>> maxv[2];
  for (int t = 0; t < 2; ++t) {
    v[t].resize(n);
    for (int i = 0; i < n; ++i) {
      if (t == 0) {
        v[t][i] = x[i] + d[i];
      } else {
        v[t][i] = -x[i] + d[i];
      }
    }
    maxv[t].assign(n, vector<ll>(n, -inf64)); 
    for (int l = 0; l < n; ++l) {
      maxv[t][l][l] = v[t][l];
      for (int r = l + 1; r < n; ++r) {
        maxv[t][l][r] = max(maxv[t][l][r - 1], v[t][r]);
      }
    }
  }

  vector<ll> prf_v(n + 1, -inf64);
  for (int i = 0; i < n; ++i) {
    chkmax(prf_v[i], -x[i] + d[i]);
    chkmax(prf_v[i + 1], prf_v[i]);
  }
  vector<ll> suf_v(n + 1, -inf64);
  for (int i = n - 1; i >= 0; --i) {
    suf_v[i] = max(suf_v[i + 1], x[i] + d[i]);
  }
  ll ans = prf_p[n - 1];
  for (int l = 0; l < n - 1; ++l) {
    for (int r = l + 1; r < n; ++r) {
      if (x[r] - x[l] <= c) continue;
      ll cur = -inf64;
      ll P = x[r] - x[l] + c;
      chkmax(cur, prf_p[l]);
      chkmax(cur, suf_p[r]);
      chkmax(cur, prf_v[l] + x[l] + c + suf_v[r] - x[r]);
      for (int i = l + 1; i < r; ++i) {
        chkmax(cur, d[i] + min(x[i] - x[l] + c, x[r] - x[i]) + suf_v[r] - x[r]);
      }
      for (int j = l + 1; j < r; ++j) {
        chkmax(cur, d[j] + min(x[r] - x[j] + c, x[j] - x[l]) + prf_v[l] + x[l]);
      }
      int j = l + 1;
      for (int i = l + 1; i + 1 < r; ++i) {
        chkmax(j, i);
        while (j + 1 < r && 2 * (x[j + 1] - x[i]) <= P) {
          ++j;
        }
        chkmax(cur, d[i] + maxv[0][i][j] - x[i]);
        chkmax(cur, d[i] + maxv[1][j + 1][r - 1] + x[i] + P);
        /*for (int j = i + 1; j < r; ++j) {
          chkmax(cur, d[i] + d[j] + min(x[j] - x[i], x[i] - x[l] + c + x[r] - x[j]));
        }*/
      }
      chkmin(ans, cur);
    }
  }
  return ans;
}


#ifdef DEBUG
int32_t main() {
#ifdef DEBUG
  freopen("in", "r", stdin);
#endif
  ios::sync_with_stdio(0);
  cin.tie(0);

  int n, c;
  cin >> n >> c;
  vector<int> l(n - 1), d(n);
  for (int& x : l) cin >> x;
  for (int& x : d) cin >> x;
  cout << find_shortcut(n, l, d, c) << '\n';

  return 0;
}
#endif

• Subtask 1: 9 / 9
• Subtask 2: 14 / 14
• Subtask 3: 8 / 8
• Subtask 4: 7 / 7
• Subtask 5: 0 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3