Submission #503576

#	Time	Username	Problem	Language	Result	Execution time	Memory
503576		cig32	Growing Vegetables is Fun 4 (JOI21_ho_t1)	C++17	100 / 100	26 ms	5424 KiB

Main

#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
mt19937_64 rng((int)std::chrono::steady_clock::now().time_since_epoch().count());
const int MAXN = 3e5 + 10;
const int MOD = 1e9 + 7;
#define int long long

int rnd(int x, int y) { // random number generator
    int u= uniform_int_distribution<int>(x, y)(rng); return u;
}

void solve(int tc) {
    int N;
    cin >> N;
    int a[N+1];
    for(int i=1; i<=N; i++) cin >> a[i];
    if(N == 2) {
        cout << (a[1] == a[2] ? 1 : 0) << "\n";
        return;
    }
    int l = 2, r = N - 1, d = 0, ans = 0;
    int now[N+1] = {};
    while(l <= r) {
        if(!now[l]) a[l] += d;
        if(!now[r] && l != r) a[r] += d;
        now[l] = now[r] = 1;
        int x = max(0ll, a[l-1] + 1 - a[l]);
        int y = max(0ll, a[r+1] + 1 - a[r]);
        d += min(x, y);
        ans += min(x, y);
        a[l] += min(x, y);
        if(l != r) a[r] += min(x, y);
        if(x < y) l++;
        else r--;
    }
    if(a[l] == a[r] && l != r) ans++;
    cout << ans << "\n";
}
int32_t main(){
    ios::sync_with_stdio(0); cin.tie(0);
    int t = 1; //cin >> t;
    for(int i=1; i<=t; i++) solve(i);
}

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