Submission #387886

#	Time	Username	Problem	Language	Result	Execution time	Memory
387886		AmineTrabelsi	Boxes with souvenirs (IOI15_boxes)	C++14	100 / 100	768 ms	372164 KiB

boxes

#include <bits/stdc++.h>
#include "boxes.h"
using namespace std;
typedef long long ll;
const int M = 1e7+5;
ll delivery(int N, int K, int L, int p[]) {
    vector<ll> l(N+1,0),r(N+1,0),cnt(N+1,0);
    for(int i=0;i<N;i++){
        // prefix
        cnt[i%K] += p[i]*2;
        l[i] = cnt[i%K];
    }
    cnt.assign(N+1,0);
    for(int i=N-1;i>=0;i--){
        // suffix
        cnt[i%K] += 2*(L-p[i]);
        r[i] = cnt[i%K];
    }
    ll ans = 1e18;   
    for(int i=0;i<=N;i++){
        // calc best answer
        ans = min(ans,(i ? l[i-1] : 0)+r[i]);
    }
    for(int i=0;i<=N-K;i++){
        // best answer with a full circle turn (max 1)
        ans = min(ans,(i ? l[i-1] : 0)+r[i+K]+L);
    }
    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