Submission #854132

#	Time	Username	Problem	Language	Result	Execution time	Memory
854132		BrineTw	Growing Vegetables is Fun 4 (JOI21_ho_t1)	C++14	100 / 100	21 ms	2136 KiB

Main

#pragma GCC optimize("O3")
#include <bits/stdc++.h>

#define debug(x) cerr << #x << ' ' << x << '\n'
#define endl '\n'
#define printv(v) cerr << #v << ": "; for (auto& n: v) cerr << setw(3) << n << " \n"[&n==&v.back()]

using namespace std;

const int M = 1e9 + 7;
typedef long long ll;


int main() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);

    int N;
    cin >> N;

    vector<ll> v(N + 2);
    for (int i = 1; i <= N; i++) cin >> v[i];    

    int l = 1, r = N; 
    ll ans = 0;
    
    while (r > l) {
        while (v[l] > v[l - 1] || v[r] > v[r + 1]) {
            if (v[l] > v[l - 1]) l++;
            if (v[r] > v[r + 1]) r--;
        }
        if (r <= l) break;
        
        int d = min(v[l - 1] + 1 - v[l], v[r + 1] + 1 - v[r]);
        v[l - 1] -= d;
        v[r + 1] -= d;
        ans += d;
        //cerr << l << ' ' << r << ' ' << d << '\n';
    }
    if (l == r || l == r + 1) {
        //cerr << "last: " << l << ' ' << r << '\n';

        ans += min(v[l - 1] - v[l] + 1, v[r + 1] - v[r] + 1);
    }
    cout << ans << '\n';

    return 0;   
}

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