Submission #374917

#	Time	Username	Problem	Language	Result	Execution time	Memory
374917		idk321	선물상자 (IOI15_boxes)	C++11	0 / 100	1 ms	492 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 i = 0; i <= 1; i++)
    {
        int a = 0;
        int b = n;
        ll cur = M;
        while (b - a > 1)
        {
            int mid = ( a + b) / 2;

            ll val1 = dp1[i] + (ll)mid * l * k + dp2[max<ll>(0, n - i- (ll)mid * k)];
            ll val2 = dp1[i] + (ll)mid * l * (k + 1) + dp2[max<ll>(0, n - i- (ll)mid * (k + 1))];
            res = min(val1, res);
            res = min(val2, res);
            if (val1 < val2)
            {
                b = mid;
            } else
            {
                a = mid;
            }
        }
    }



    return res;
}

/*
5 5 100
1 3 6 53 78

*/

Compilation message (stderr)

boxes.cpp: In function 'long long int delivery(int, int, int, int*)':
boxes.cpp:37:12: warning: unused variable 'cur' [-Wunused-variable]
   37 |         ll cur = M;
      |            ^~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30