Submission #100167

#	Time	Username	Problem	Language	Result	Execution time	Memory
100167		luciocf	Boxes with souvenirs (IOI15_boxes)	C++14	25 / 100	4 ms	512 KiB

boxes

#include <bits/stdc++.h>
#include "boxes.h"
 
using namespace std;
 
const int maxn = 1e7+10;
 
typedef long long ll;
 
int p[maxn];
 
ll pref[maxn], suf[maxn];
 
long long delivery(int N, int K, int L, int positions[])
{
	int n = N, k = K;
	for (int i = 1; i <= n; i++)
		p[i] = positions[i-1];
 
	int mid = L/2;
	int last_p = 0, last_s = n+1;
 
	if (p[1] < mid) pref[1] = 2ll*(ll)p[1], last_p = 1;
	for (int i = 2; i <= n; i++)
	{
		if (p[i] >= mid) break;
 
		pref[i] = 2ll*(ll)p[i] + pref[max(0, i-k)];
		last_p = i;
	}
 
	if (p[n] >= mid) suf[n] = 2ll*((ll)L-(ll)p[n]), last_s = n;
 
	for (int i = n-1; i >= 1; i--)
	{
		if (p[i] < mid) break;
 
		suf[i] = 2ll*((ll)L-(ll)p[i]) + suf[min(n+1, i+k)];
		last_s = i;
	}
 
	ll ans = pref[last_p] + suf[last_s];
 
	for (int i = 1; i <= n; i++)
	{
		for (int j = 1; j <= k; j++)
		{
			if (!last_p && last_s > n) break;
 
			if (!last_p) last_s++;
			else if (last_s > n) last_p--;
			else if (p[last_p] > L-p[last_s]) last_p--;
			else last_s++;
		}
 
		ans = min(ans, 1ll*(ll)i*(ll)L + pref[last_p] + suf[last_s]);
	}
 
	return ans;
}

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