Submission #374920

#	Time	Username	Problem	Language	Result	Execution time	Memory
374920		idk321	선물상자 (IOI15_boxes)	C++11	100 / 100	559 ms	231728 KiB

boxes

#include "boxes.h"

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

const ll M = 1000000000000000000LL;

long long delivery(int n, int k, int l, int p[]) {


    vector<ll> dp1(n + 1, M);
    dp1[0] = 0;
    for (int i = 0; i < n; i++)
    {
        dp1[i + 1] = dp1[max(0, i + 1 - k)] + 2 * p[i];
    }

    vector<ll> dp2(n + 1, M);
    dp2[0] = 0;
    for (int i = 0, j = n - 1; i < n; i++, j--)
    {
        dp2[i + 1] = dp2[max(0, i + 1 - k)] + 2 *  (l - p[j]);
    }



    ll res = M;

    int atLeast = n / k;
    if (n % k != 0) atLeast++;
    res = min(res, (ll) atLeast * l);


    for (int cycle = 0; cycle <= 1; cycle++)
    {
        ll cur = l;
        cur *= cycle;
        for (int i = 0; i + (ll) cycle * k <=n; i++)
        {
            ll cur2 = cur;
            cur2 += dp1[i];
            cur2 += dp2[n - i - cycle * k];
            res = min(res, cur2);
        }
        if ((ll) cycle * k >= n)
        {
            res = min(res, cur);
        }
    }



    return res;
}

/*
5 5 100
1 3 6 53 78

*/

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