제출 #861244

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
861244		sleepntsheep	쌀 창고 (IOI11_ricehub)	C++17	100 / 100	27 ms	3676 KiB

ricehub

#include <iostream>
#include <vector>
#include <algorithm>
#include <deque>
#include <set>
#include <utility>
#include <array>
#include "ricehub.h"

using namespace std;
#define ALL(x) x.begin(), x.end()
#define N 100005
using ll = long long;

int n, l, z = -1;
ll b, p[N], a[N];

int optimal_hub(int l, int r)
{
    return (l+r)/2;
}

ll sum(int l, int r)
{
    return p[r] - p[l-1];
}

ll need_budget(int l, int r, int h)
{
    if (h < l || r < h) return 1e18;
    return a[h] * (h-l+1) - a[h] * (r-h) + sum(h+1, r) - sum(l, h);
}

ll need_budget(int l, int r)
{
    return min({need_budget(l, r, optimal_hub(l, r)),
            need_budget(l, r, optimal_hub(l, r) + 1), 
            need_budget(l, r, optimal_hub(l, r) - 1)});
}

int besthub(int n, int l, int *a_, ll b)
{
    ::b = b; ::n = n;
    for (int i = 1;i  <=n; ++i) a[i]=a_[i-1];
    for (int i = 1; i <= n; ++i) 
    {
        p[i] = p[i-1] + a[i];
        int l = 1, r = i;
        while (l <= r)
        {
            int y = (l+r)/2;
            if (need_budget(y, i) <= b)
                z = max(z, i-y+1), r = y - 1;
            else l = y + 1;
        }
    }
    return z;
}

• Subtask 1: 17 / 17
• Subtask 2: 25 / 25
• Subtask 3: 26 / 26
• Subtask 4: 32 / 32