Submission #802032

#	Time	Username	Problem	Language	Result	Execution time	Memory
802032		Sohsoh84	Giraffes (JOI22_giraffes)	C++17	10 / 100	1697 ms	340 KiB

giraffes

// Wounds should become scars but I'm cracked instead U+1FAE0
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;

#define all(x)			(x).begin(),(x).end()
#define X			first
#define Y			second
#define sep			' '
#define endl			'\n'
#define debug(x)		cerr << #x << ": " <<  x << endl;

const ll MAXN = 1e6 + 10;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int n, T[MAXN], P[MAXN], F[MAXN], ind[MAXN];

inline int rand_perm() {
	int l = 1, r = n;
	int fl = 1, fr = n;
	int ans = n;
	
	for (int i = 1; i <= n; i++) {
		if (P[l] == fl) {
			ans--;
			l++;
			fl++;
		} else if (P[l] == fr) {
			ans--;
			l++;
			fr--;
		} else if (P[r] == fl) {
			ans--;
			r--;
			fl++;
		} else if (P[r] == fr) {
			ans--;
			r--;
			fr--;
		} else {
			int tfl = fl;
			int tfr = fr;
			
			if (ind[tfl] < l || ind[tfl] > r) tfl++;
			else if (ind[tfr] < l || ind[tfr] > r) tfr--;
			else {
				int x = rng() % 2;
				if (x) tfl++;
				else tfr--;
			}

			if (P[l] < fl || P[l] > fr) l++;
			else if (P[r] < fl || P[r] > fr) r--;
			else if (rng() % 2) l++;
			else r--;

			fl = tfl;
			fr = tfr;
		}
	}

	return ans;
}
 
int main() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> P[i];
		ind[P[i]] = i;
	}

	int fuck = 10000000 * 13 / n;

	int ans = n;
	while (fuck--) {
		ans = min(ans, rand_perm());
	}

	cout << ans << endl;
	return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 22
• Subtask 3: 0 / 27
• Subtask 4: 0 / 41