Submission #1145252

#	Time	Username	Problem	Language	Result	Execution time	Memory
1145252		thangdz2k7	Boxes with souvenirs (IOI15_boxes)	C++20	10 / 100	0 ms	332 KiB

boxes

#ifdef EVAL

#include "boxes.h"

#endif // EVAL

#include <bits/stdc++.h>

using namespace std;

const int MaxN = 1e7 + 5;
const long long inf = 1e18;

int pos[MaxN], n, k, len;
long long dp[MaxN];

int cost(int le, int ri){
    if (pos[ri] <= len / 2) return pos[ri] * 2;
    if (pos[le] > len / 2) return (len - pos[le]) * 2;
    return len;
}

struct dq{
    int a[MaxN], ptrL = 1, ptrR = 0;

    void fix(int i){
        while (ptrL <= ptrR && i - a[ptrL] > k)
            ptrL ++;
    }

    long long val[MaxN];

    void add(int i, long long v){
        val[i] = v;
        while (ptrR >= ptrL && val[a[ptrR]] >= v)
            ptrR --;

        a[++ ptrR] = i;
    }

    long long get(){
        return val[a[ptrR]];
    }

} h1, h2;

long long delivery(int N, int K, int L, int position[]){
    n = N, k = K, len = L;
    for (int i = n - 1; i >= 0; -- i)
        pos[i + 1] = position[i];

    dp[0] = 0;

    for (int i = 1; i <= n; ++ i){
        dp[i] = dp[max(0, i - k)] + len;
        h1.fix(i); h2.fix(i);
        h1.add(i - 1, dp[i - 1]);
        if (pos[i] > len / 2) h2.add(i - 1, dp[i - 1] + (len - pos[i]) * 2);

        if (pos[i] <= len / 2) dp[i] = min(dp[i], h1.get() + pos[i] * 2);
        else dp[i] = min(dp[i], h2.get());

    }

    return dp[n];
}

#ifndef EVAL

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    cin >> n >> k >> len;

    for (int i = 0; i < n; ++ i)
        cin >> pos[i];

    cout << delivery(n, k, len, pos);
}

/*
5 1 5
1 3 3 3 4
*/

#endif // EVAL

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