Submission #1073851

#	Time	Username	Problem	Language	Result	Execution time	Memory
1073851		ArthuroWich	Ancient Books (IOI17_books)	C++17	12 / 100	1 ms	348 KiB

books

#include "books.h"
#include<bits/stdc++.h>
using namespace std;
long long minimum_walk(vector<int> p, int s) {
	long long int ans = 0, n = p.size();
	for (int i = 0; i < n; i++) {
		ans += abs(i-p[i]);
	}
	vector<pair<int, int>> cycles;
	for (int i = 0; i < n; i++) {
		if (p[i] == i) {
			continue;
		}
		int a = i, l = i, r = i;
		a = p[i];
		l = min(l, a);
		r = max(r, a);
		while(a != i) {
			a = p[a];
			l = min(l, a);
			r = max(r, a);
		}
		cycles.push_back({l, r});
	}
	vector<int> pref(n+1, 0), f1(n, 0), f2(n, 0);
	for (auto [i, j] : cycles) {
		pref[i] += 1;
		pref[j+1] -= 1; 
	}
	for (int i = 1; i < n; i++) {
		pref[i] += pref[i-1];
	}
	for (int i = n-1; i >= 0; i--) {
		if (pref[i] > 0) {
			f2[i] = 1;
		}
		if (i < n-1) {
			f2[i] |= f2[i+1];
		}
	}
	for (int i = n-1; i >= 0; i--) {
		if (f2[i] && pref[i] == 0) {
			ans += 2;
		}
	}
	return ans;
}

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