Submission #63907

#	Time	Username	Problem	Language	Result	Execution time	Memory
63907		Kubalionzzale	Boxes with souvenirs (IOI15_boxes)	C++14	20 / 100	2 ms	420 KiB

boxes

#include "boxes.h"
#include <map>
#include <iostream>
#include <algorithm>

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

    if (n == 1)
    {
        return std::min(p[0] * 2LL, (l - p[0]) * 2LL);
    }

    int here = n;
    for (int i = 0; i < n; ++i)
    {
        if (p[i] > l - p[i] && here == n)
        {
            here = i;
        }
        if (i >= here)
        {
            p[i] = l - p[i];
        }
    }

    if (here == 0)
    {
        int cur = k - 1;
        long long int sum = p[n - 1];
        for (int i = n - 2; i >= 0; --i)
        {
            if (cur == 0)
            {
                sum += p[i + 1] * 2LL + p[i] - p[i + 1];
                cur = k - 1;
            }
            else
            {
                sum += p[i] - p[i + 1] * 1LL;
                --cur;
            }
        }

        return sum + p[0] * 1LL;
    }
    else if (here == n)
    {
        int cur = k - 1;
        long long int sum = p[0];
        for (int i = 1; i < n; ++i)
        {
            if (cur == 0)
            {
                sum += p[i - 1] * 2LL + p[i] - p[i - 1];
                cur = k - 1;
            }
            else
            {
                sum += p[i] - p[i - 1] * 1LL;
                --cur;
            }
        }

        return sum + p[n - 1] * 1LL;
    }

    long long int sumleft = p[here - 1], leftleft = -1;
    int cur = k - 1;

    for (int i = here - 2; i >= 0; --i)
    {
        if (cur == 0)
        {
            sumleft += p[i + 1] + p[i] * 1LL;
            cur = k - 1;
        }
        else
        {
            sumleft += p[i + 1] - p[i] * 1LL;
            --cur;
        }
    }

    sumleft += p[0];

    long long int sumright = p[here], leftright = -1;
    cur = k - 1;

    for (int i = here + 1; i < n; ++i)
    {
        if (cur == 0)
        {
            sumright += p[i - 1] + p[i] * 1LL;
            cur = k - 1;
        }
        else
        {
            sumright += p[i - 1] - p[i] * 1LL;
            --cur;
        }
    }

    sumright += p[n - 1];
    leftright = cur;

    long long int curmin = sumleft + sumright;

    if (k == 1)
        return curmin;

    long long int curval, max = 0;
    int where = std::max(here - k + 1, 0);
    for (int i = std::max(here - k + 1, 0);; ++i)
    {
        if (i >= here)
            break;
        if (i + k - 1 >= n)
            break;

        curval = 0;
        if (i - 1 > 0)
        {
            curval += p[i] - p[i - 1] * 1LL;
        }
        else
        {
            curval += p[i] * 1LL;
        }

        if (i + k < n)
        {
            if (i + k == here)
            {
                curval += (l - p[i + k]) * 1LL - p[i + k - 1];
            }
            else
            {
                curval += p[i + k - 1] - p[i + k] * 1LL;
            }
        }
        else
        {
            curval += p[i + k - 1] * 1LL;
        }

        if (curval > max)
        {
            max = curval;
            where = i;
        }
    }

    long long int cursum = l;
    if (where != 0)
    {
        cur = k - 1;
        cursum += p[where - 1];

        for (int i = where - 2; i >= 0; --i)
        {
            if (cur == 0)
            {
                cursum += p[i + 1] + p[i] * 1LL;
                cur = k - 1;
            }
            else
            {
                cursum += p[i + 1] - p[i] * 1LL;
                --cur;
            }
        }

        cursum += p[0];
    }

    if (where + k - 1 != n - 1)
    {
        cur = k - 1;
        cursum += p[where + k];

        for (int i = where + k + 1; i < n; ++i)
        {
            if (cur == 0)
            {
                cursum += p[i - 1] + p[i] * 1LL;
                cur = k - 1;
            }
            else
            {
                cursum += p[i - 1] - p[i] * 1LL;
                --cur;
            }
        }

        cursum += p[n - 1];
    }

    return std::min(curmin, cursum);
}

Compilation message (stderr)

boxes.cpp: In function 'long long int delivery(int, int, int, int*)':
boxes.cpp:67:42: warning: unused variable 'leftleft' [-Wunused-variable]
     long long int sumleft = p[here - 1], leftleft = -1;
                                          ^~~~~~~~
boxes.cpp:86:39: warning: variable 'leftright' set but not used [-Wunused-but-set-variable]
     long long int sumright = p[here], leftright = -1;
                                       ^~~~~~~~~

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