Submission #588434

#	Time	Username	Problem	Language	Result	Execution time	Memory
588434		lorenzoferrari	Boxes with souvenirs (IOI15_boxes)	C++17	100 / 100	508 ms	198552 KiB

boxes

#include "boxes.h"
#pragma GCC optimize ("O3")
#include <bits/stdc++.h>
using namespace std;
using LL = long long;

inline vector<LL> linear_cost(int n, int k, int p[]) {
  vector<LL> ans(n+1); ans[0] = 0;
  for (int i = 1; i <= n; ++i) {
    ans[i] = 2 * p[i-1] + ans[max(0, i - k)];
    ans[i] = max(ans[i], ans[i-1]); // case p[n-1] = 0...
  }
  return ans;
}

LL delivery(int n, int k, int l, int p[]) {
  auto ca = linear_cost(n, k, p);
  for (int i = 0; i < n; ++i) p[i] = (p[i] ? l - p[i] : 0);
  reverse(p, p + n);
  auto cb = linear_cost(n, k, p);
  LL ans = 1e18;
  for (int i = 0; i <= n; ++i) {
    ans = min(ans, ca[i] + cb[n - i]);
  }
  for (int a = 0; a < n; ++a) {
    int b = min(n, a + k);
    ans = min(ans, l + ca[a] + cb[n - b]);
  }
  return ans;
}

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