Submission #894643

#	Time	Username	Problem	Language	Result	Execution time	Memory
894643		DEQK	Giraffes (JOI22_giraffes)	C++17	0 / 100	0 ms	348 KiB

giraffes

#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define sz(a) ((int) a.size())
#define F first 
#define S second
const int N = 8e3 + 15;
int n, p[N];
void solve() {
	vector<vector<int>> dp(4, vector<int> (n + 1, 0));
	int ans = 1;
	while(1) {
		vector<pair<int, pair<int, int>>> sq;
		for(int i = 0; i < 4; i++) {
			for(int j = 1; j <= n; j++) {
				if(dp[i][j] == 1e9) continue;
				int x = j - (i >= 2 ? dp[i][j] : 0);
				int y = p[j] - (i % 2 ? dp[i][j] : 0);
				sq.pb({dp[i][j], {x, y}});
			}
		}
		dp = vector<vector<int>> (4, vector<int> (n + 1, 1e9));
		for(int i = 0; i < 4; i++) {
			for(int j = 1; j <= n; j++) {
				int len = 1e9;
				for(int k = 0; k < sz(sq); k++) {
					int dx = (i >= 2 ? j - (sq[k].S.F + sq[k].F) : sq[k].S.F - j);
					int dy = (i % 2 ? p[j] - (sq[k].S.S + sq[k].F) : sq[k].S.S - p[j]);
					if(dx > 0 && dy > 0) {
						len = min(len, sq[k].F + max(dx, dy));
					}
				}
				int a = (i >= 2 ? j - 1 : N - j);
				int b = (i % 2 ? p[j] - 1 : N - p[j]);
				if(len <= min(a, b)) {
					dp[i][j] = len;
				}
			}
		}
		if(dp == vector<vector<int>> (4, vector<int> (n + 1, 1e9))) {
			break;
		}
		ans += 1;
	}
	cout << n - ans << '\n';
}
int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	int n;
	cin >> n;
	for(int i = 1; i <= n; i++) {
		cin >> p[i];
	}
	solve();
    return 0;
}

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