Submission #602252

#	Time	Username	Problem	Language	Result	Execution time	Memory
602252		SamAnd	Growing Vegetables is Fun 4 (JOI21_ho_t1)	C++17	100 / 100	27 ms	4312 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define fi first
#define se second
typedef long long ll;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
mt19937 rnf(2106);
const int N = 200005;
const ll INF = 1000000009000000009;

int n;
int a[N];

ll p[N], s[N];

void solv()
{
    cin >> n;
    for (int i = 1; i <= n; ++i)
        cin >> a[i];

    for (int i = 1; i <= n; ++i)
    {
        p[i] = p[i - 1];
        if (a[i] <= a[i - 1])
            p[i] += (a[i - 1] + 1 - a[i]);
    }
    for (int i = n; i >= 1; --i)
    {
        s[i] = s[i + 1];
        if (a[i] <= a[i + 1])
            s[i] += (a[i + 1] + 1 - a[i]);
    }

    ll ans = INF;
    for (int i = 1; i <= n; ++i)
    {
        ll x = a[i - 1], y = a[i], z = a[i + 1];
        if (p[i - 1] > s[i + 1])
        {
            x += p[i - 1] - s[i + 1];
            y += p[i - 1] - s[i + 1];
        }
        else
        {
            y += s[i + 1] - p[i - 1];
            z += s[i + 1] - p[i - 1];
        }

        ll yans = max(p[i - 1], s[i + 1]);
        if (y <= max(x, z))
            yans += max(x, z) + 1 - y;
        ans = min(ans, yans);
    }

    cout << ans << "\n";
}

int main()
{
    #ifdef SOMETHING
    freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    #endif // SOMETHING
    ios_base::sync_with_stdio(false), cin.tie(0);

    int tt = 1;
    //cin >> tt;
    while (tt--)
    {
        solv();
    }
    return 0;
}

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