Submission #301109

#	Time	Username	Problem	Language	Result	Execution time	Memory
301109		JPN20	Ancient Books (IOI17_books)	C++17	12 / 100	1 ms	384 KiB

books

#include "books.h"
#include <bits/stdc++.h>
using namespace std;

long long N;
long long cnt[1 << 18];
bool used[1 << 18];

long long minimum_walk(vector<int> p, int s) {
	N = p.size();
	for (int i = 0; i < N; i++) {
		if (used[i] == true || p[i] == i) continue;
		int cx = i;
		while (used[cx] == false) {
			int e1 = cx, e2 = p[cx]; if (e1 > e2) swap(e1, e2);
			cnt[e1] += 1;
			cnt[e2] -= 1;
			used[cx] = true;
			cx = p[cx];
		}
	}
	for (int i = 1; i < N; i++) cnt[i] += cnt[i - 1];
	
	long long sum = 0;
	for (int i = 0; i < N; i++) sum += cnt[i];
	for (int i = 1; i < N; i++) {
		if (cnt[i - 1] == 0LL && cnt[i] >= 1LL) sum += 2LL * i;
	}
	return sum;
}

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