제출 #71216

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
71216		fallingstar	선물상자 (IOI15_boxes)	C++14	10 / 100	2 ms	404 KiB

boxes

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

using namespace std;

#define long long long

const int N = 2e7 + 2;

long fsuff[N], fpref[N];

long delivery(int n, int k, int L, int p[]) {
	int head = 0;
	while (head < n && p[head] == 0) ++head;

	long res = (long) (n - head + k - 1) / k * L;

	for (int i = n - 1; i >= head; --i)
		fsuff[i] = fsuff[i + k] + (L - p[i]) * 2;

	int full = 0;
	while (full * k <= n - head && fsuff[head + (full + 1) * k] + L < fsuff[head + full * k]) ++full;

	for (int i = head; i < n; ++i)
	{
		fpref[i] = (i < k ? 0 : fpref[i - k]) + p[i] * 2;
	
		#define eval(x) (fsuff[i + 1 + (x) * k] + (long) (x) * L)	

		while (full > 0 && eval(full - 1) < eval(full)) --full;

		res = min(res, fpref[i] + eval(full));
		#undef eval
	}
    return res;
}

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