Submission #240070

#	Time	Username	Problem	Language	Result	Execution time	Memory
240070		Jatana	Ancient Books (IOI17_books)	C++17	0 / 100	8 ms	384 KiB

books

#include "books.h"
#include <vector>
#include <algorithm>
#include <iostream>
#include <cassert>

#define pb push_back
#define le(v) ((int)v.size())

using namespace std;
typedef long long ll;

int dp(vector<int> p, int s, int end) {
	if (is_sorted(p.begin(), p.end())) {
		return abs(s - end);
	} else {
		int rez = 1e9;
		for (int i = 0; i < le(p); i++) {
			if (p[i] != i) {
				int cur = abs(i - s);
				vector<int> q = p;
				int t = q[i];
				vector<int> ind{i};
				while (t != i) {
					ind.pb(t);
					t = q[t];
				}
				// for (int x : ind) {
				// 	cout << x << " ";
				// }
				// cout << endl;
				for (int i = 0; i < le(ind); i++) {
					int j = (i + 1) % le(ind);
					cur += abs(ind[i] - ind[j]);
				}
				sort(ind.begin(), ind.end());
				for (int x : ind) {
					q[x] = x;
				}	
				cur += dp(q, i, end);
				rez = min(rez, cur);
			}
		}
		return rez;
	}
}

ll minimum_walk(vector<int> p, int s) {
	// return dp(p, s, s);
	ll rez = 0;
	int buf = -1;
	while (!is_sorted(p.begin(), p.end())) {
		// cout << buf << " " << s << endl;
		// for (int x : p) {
		// 	cout << x << " ";
		// }
		// cout << endl;
		if (buf == s) {
			swap(p[s], buf);
		} else if (buf < s) {
			swap(buf, p[s]);
		}
		if (buf == -1) {
			bool ok = true;
			for (int i = s; i < le(p); i++) {
				if (p[i] != i) {
					ok = false;
				}
			}
			if (ok) {
				s--;
				rez++;
			} else {
				s++;
				rez++;
			}
		} else {
			if (buf < s) {
				s--;
			} else s++;
			rez++;
		}
	}
	rez += s;
	return rez;
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 10
• Subtask 3: 0 / 28
• Subtask 4: 0 / 20
• Subtask 5: 0 / 30