Submission #777513

#	Time	Username	Problem	Language	Result	Execution time	Memory
777513		boris_mihov	Boxes with souvenirs (IOI15_boxes)	C++17	100 / 100	712 ms	372468 KiB

boxes

#include "boxes.h"
#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>

typedef long long llong;
const int MAXN = 10000000 + 10;
const llong INF = 1e18;

int n, k, l;
std::vector <int> left;
std::vector <int> right;
llong prefix[MAXN];
llong suffix[MAXN];

llong delivery(int N, int K, int L, int p[]) 
{
    n = N;
    k = K;
    l = L;

    if (k > n) k = n;
    for (int i = 0 ; i < n ; ++i)
    {
        left.push_back(p[i]);
        right.push_back(l - p[i]);
    }

    for (int i = 0 ; i < n ; ++i)
    {
        prefix[i] = 2 * left[i];
        if (i >= k) prefix[i] += prefix[i - k];
    }

    for (int i = n - 1 ; i >= 0 ; --i)
    {
        suffix[i] = 2 * right[i];
        if (i + k < n) suffix[i] += suffix[i + k];
    }

    llong ans = suffix[0];
    for (int i = 0 ; i < n ; ++i)
    {
        ans = std::min(ans, prefix[i] + suffix[i + 1]);
    }
    
    for (int i = 0 ; i + k <= n ; ++i)
    {
        llong curr = l + suffix[i + k];
        if (i > 0) curr += prefix[i - 1];
        ans = std::min(ans, curr);
    }

    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