Submission #236098

#	Time	Username	Problem	Language	Result	Execution time	Memory
236098		quocnguyen1012	Boxes with souvenirs (IOI15_boxes)	C++14	100 / 100	598 ms	202616 KiB

boxes

#ifndef LOCAL
#include "boxes.h"
#endif // LOCAL

#include <bits/stdc++.h>

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define ar array

using namespace std;
typedef long long ll;
typedef pair<int, int> ii;

const int maxn = 1e7 + 5;

ll f[maxn][2];

long long delivery(int N, int K, int L, int p[])
{
  for(int i = 0; i < N; ++i){
    if(i < K) f[i][0] = 2 * p[i];
    else f[i][0] = f[i - K][0] + 2 * p[i];
  }
  for(int i = N - 1; i >= 0; --i){
    if(i + K >= N) f[i][1] = 2 * (L - p[i]);
    else f[i][1] = f[i + K][1] + 2 * (L - p[i]);
  }
  ll res = min(f[N - 1][0], f[0][1]);
  for(int i = -1; i < N - 1; ++i){
    res = min(res, (i == -1 ? 0 : f[i][0]) + L + f[min(N, i + K + 1)][1]);
  }
  for(int i = N; i >= 0; --i){
    res = min(res, f[i][1] + L + (i - K - 1 >= 0 ? f[i - K - 1][0] : 0));
  }
  for(int i = 0; i < N - 1; ++i){
    res = min(res, f[i][0] + f[i + 1][1]);
  }
  return res;
}

#ifdef LOCAL
signed main(void)
{
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  #ifdef LOCAL
    freopen("A.INP", "r", stdin);
    freopen("A.OUT", "w", stdout);
  #endif // LOCAL
  int _N, _K, _L;
  cin >> _N >> _K >> _L;
  int p[_N];
  for(int i = 0; i < _N; ++i)
    cin >> p[i];
  cout << delivery(_N, _K, _L, p);
}
#endif // LOCAL

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 30 / 30