Submission #612413

#	Time	Username	Problem	Language	Result	Execution time	Memory
612413		cheissmart	Giraffes (JOI22_giraffes)	C++14	10 / 100	1885 ms	1048576 KiB

giraffes

#include <bits/stdc++.h>
#define IO_OP std::ios::sync_with_stdio(0); std::cin.tie(0);
#define F first
#define S second
#define V vector
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(), (v).end()

using namespace std;

typedef long long ll;
typedef pair<int, int> pi;
typedef V<int> vi;

string _reset = "\u001b[0m", _yellow = "\u001b[33m", _bold = "\u001b[1m";
void DBG() { cerr << "]" << _reset << endl; }
template<class H, class...T> void DBG(H h, T ...t) {
	cerr << to_string(h);
	if(sizeof ...(t)) cerr << ", ";
	DBG(t...);
}
#ifdef CHEISSMART
#define debug(...) cerr << _yellow << _bold << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define debug(...)
#endif

const int INF = 1e9 + 7;

signed main()
{
	IO_OP;

	int n;
	cin >> n;
	vi p(n);
	for(int i = 0; i < n; i++) {
		cin >> p[i];
		p[i]--;
	}
	int ans = INF;

	auto go = [&] (vi q) {
		vi iq(n);
		for(int i = 0; i < n; i++)
			iq[q[i]] = i;
		vi pp;
		for(int i:p)
			pp.PB(iq[i]);

		int tt = 0;
		for(int i = 0; i < n; i++) {
			if(pp[i] != i) {
				tt++;
			}
		}
		ans = min(ans, tt);
	};
	auto ok = [&] (vi a) {
		int l = 0, r = n - 1, lb = 0, rb = n - 1;
		while(r - l + 1 >= 4) {
			if(a[l] != lb && a[l] != rb && a[r] != lb && a[r] != rb)
				return false;
			if(a[l] == lb)
				l++, lb++;
			else if(a[l] == rb)
				l++, rb--;
			else if(a[r] == lb)
				r--, lb++;
			else
				r--, rb--;
		}
		return true;
	};

	V<V<vi>> dp(n, V<vi>());
	dp[0].PB(vi{0});
	for(int len = 1; len < n; len++) {
		for(vi q:dp[len - 1]) {
			{
				vi qq = q;
				qq.PB(len);
				dp[len].PB(qq);
			}
			{
				vi qq = q;
				qq.insert(qq.begin(), len);
				dp[len].PB(qq);
			}
		}

		for(vi q:dp[len - 1]) {
			for(int&e:q) e++;
			{
				vi qq = q;
				qq.PB(0);
				dp[len].PB(qq);
			}
			{
				vi qq = q;
				qq.insert(qq.begin(), 0);
				dp[len].PB(qq);
			}
		}
	}
	for(vi q:dp[n - 1])
		go(q);

	cout << ans << '\n';

}

Compilation message (stderr)

giraffes.cpp: In function 'int main()':
giraffes.cpp:62:7: warning: variable 'ok' set but not used [-Wunused-but-set-variable]
   62 |  auto ok = [&] (vi a) {
      |       ^~

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