제출 #655695

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
655695		benjaminkleyn	Rice Hub (IOI11_ricehub)	C++17	100 / 100	117 ms	2364 KiB

ricehub

#include <bits/stdc++.h>
#include "ricehub.h"
using namespace std;
typedef long long ll;

ll pref[100001], x[100000];

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

ll cost(int l, int r, int i)
{
    return sum(i + 1, r) + x[i] * (2 * i - l - r) - sum(l, i - 1);
}

ll find_min(int l, int r)
{
    int lo = l, hi = r;
    while (hi - lo >= 3)
    {
        int m1 = lo + (hi - lo) / 3;
        int m2 = hi - (hi - lo) / 3;
        if (cost(l, r, m1) < cost(l, r, m2))
            hi = m2 - 1;
        else
            lo = m1;
    }
    for (int i = lo + 1; i <= hi; i++)
        if (cost(l, r, i) < cost(l, r, lo))
            lo = i;
    return cost(l, r, lo);
}

ll calc(int R, int X[], int cnt)
{
    ll mn = LLONG_MAX;
    for (int l = 0, r = cnt - 1; r < R; l++, r++)
        mn = min(mn, find_min(l, r));
    return mn;
}

int besthub(int R, int L, int X[], ll B) 
{
    for (int i = 0; i < R; i++)
        x[i] = X[i], pref[i + 1] = pref[i] + X[i];

    int lo = 0, hi = R;
    while (lo < hi)
    {
        int mid = (lo + hi + 1) / 2;

        if (calc(R, X, mid) <= B)
            lo = mid;
        else hi = mid - 1;
    }
    return lo;
}

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