Submission #153027

#	Time	Username	Problem	Language	Result	Execution time	Memory
153027		mieszko11b	Ancient Books (IOI17_books)	C++14	22 / 100	168 ms	16380 KiB

books

#include "books.h"
#include <bits/stdc++.h>

using ll = long long;

using namespace std;

int n;
bool vis[1007];
ll dist[1007];

long long minimum_walk(std::vector<int> p, int s) {
	ll res = 0;
	n = p.size();

	for(int i = 0 ; i < n ; i++) {
		if(vis[i])
			continue;
			
		int w = i;
		while(!vis[w]) {
			vis[w] = 1;
			res += abs(p[w] - w);
			w = p[w];
		}
	}

	for(int i = 0 ; i < n ; i++)
		dist[i] = 1e9;
	dist[s] = 0;
	memset(vis, 0, sizeof vis);
	
	deque<int> Q;
	Q.push_front(s);
	
	while(!Q.empty()) {
		int w = Q.front();
		Q.pop_front();
		
		vis[w] = 1;
		
		int a, b;
		if(p[w] >= w)
			a = w + 1, b = p[w];
		else
			a = p[w], b = w - 1;
			
		for(int x = a ; x <= b ; x++)
			if(!vis[x])
				dist[x] = min(dist[x], dist[w]), Q.push_front(x);


		if(w + 1 < n && !vis[w + 1]) {
			dist[w + 1] = min(dist[w + 1], dist[w] + 1);
			Q.push_back(w + 1);
		}
		
		if(w - 1 >= 0 && !vis[w - 1]) {
			dist[w - 1] = min(dist[w - 1], dist[w] + 1);
			Q.push_back(w - 1);
		}
	}
	
	ll maxd = 0;
	for(int i = 0 ; i < n ; i++)
		if(i != p[i])
			maxd = max(maxd, dist[i]);

	return res + maxd * 2;
}

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