Submission #833521

#	Time	Username	Problem	Language	Result	Execution time	Memory
833521		caganyanmaz	Ancient Books (IOI17_books)	C++17	0 / 100	8 ms	15956 KiB

books

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

//#define DEBUGGING
#ifdef DEBUGGING
#include "../debug.h"
#else
#define debug(x...) void(42)
#endif

struct Node
{
	int head, tail, size, nxt;
	Node(int i) : head(i), tail(i), size(1), nxt(-1) {}
	Node() : Node(-1) {}

};

constexpr static int MXN = 1e6;
Node node[MXN];
bitset<MXN> visited;


void merge(int a, int b);

ll minimum_walk(vector<int> p, int s) 
{
	ll sum = 0;
	int n = p.size();
	debug("A");
	for (int i = 0; i < n; i++)
		sum += abs(p[i] - i);
	debug("B");
	for (int i = 0; i < n; i++)
		node[i] = Node(i);
	debug("c");
	for (int i = 0; i < n; i++)
		if (node[i].head != node[p[i]].head)
			merge(node[i].head, node[p[i]].head);
	for (int i = 0; i < n; i++)
		debug(i, node[i].head);
	int counter = 0;
	for (int i = 0; i < n; i++)
		if (node[i].head == i)
			counter++;
	debug(sum);
	debug("D");
	int lle = s, lri = s;
	for (int i = s; i >= 0; i--)
	{
		while (counter > 0)
		{

			for (int j = 0; j < n; j++)
			{
				int lpos = lle-j;
				int rpos = lri+j;
				if (lpos >= 0 && !visited[node[lpos].head])
				{
					sum += j*2;
					lle = lpos;
					visited[node[lpos].head] = true;
					counter--;
					break;
				}
				if (rpos < n && !visited[node[rpos].head])
				{
					sum += j*2;
					lri = rpos;
					visited[node[rpos].head] = true;
					counter--;
					break;
				}
			}
		}
	}
	return sum;
}

void merge(int a, int b)
{
	if (node[a].size < node[b].size) swap(a, b);
	node[a].size += node[b].size;
	node[node[a].tail].nxt = b;
	node[a].tail = node[b].tail;
	for (;b!=-1;b=node[b].nxt)
		node[b].head = a;
}

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