Submission #625129

#	Time	Username	Problem	Language	Result	Execution time	Memory
625129		boris_mihov	Growing Vegetables is Fun 4 (JOI21_ho_t1)	C++14	0 / 100	1 ms	340 KiB

Main

#include <algorithm>
#include <iostream>
#include <numeric>
#include <vector>

typedef long long llong;
const int MAXN = 5000 + 10;
const int INF  = 1e9;

int a[MAXN], n;
llong prefix[MAXN];
llong suffix[MAXN];
llong prefVal[MAXN];
llong suffVal[MAXN];
void solve()
{
    prefVal[1] = a[1];
    suffVal[n] = a[n];
    int last = a[1];
    prefix[1] = suffix[n] = 0;
    for (int i = 2 ; i <= n ; ++i)
    {
        prefix[i] = prefix[i-1] + std::max(0, last + 1 - a[i]);
        last = std::max(last + 1, a[i]);
        prefVal[i] = last;
    }

    last = a[n];
    llong ans = prefix[n];
    for (int i = n-1 ; i >= 0 ; --i)
    {
        suffix[i] = suffix[i+1] + std::max(0, last + 1 - a[i]);
        last = std::max(last + 1, a[i]);
        suffVal[i] = last;
    }

    for (int i = 0 ; i <= n ; ++i)
    {
        ans = std::min(ans, std::max(prefix[i], suffix[i + 1]) + (prefVal[i] == suffVal[i + 1] && prefix[i] == suffix[i + 1]));
    }

    std::cout << ans << '\n';
}

void read()
{
    std::cin >> n;
    for (int i = 1 ; i <= n ; ++i)
    {
        std::cin >> a[i];
    }
}

void fastIO()
{
    std::ios_base :: sync_with_stdio(0);
    std::cout.tie(nullptr);
    std::cin.tie(nullptr);
}

int main()
{
    fastIO();
    read();
    solve();

    return 0;
}

• Subtask 1: 0 / 40
• Subtask 2: 0 / 60