Submission #73456

#	Time	Username	Problem	Language	Result	Execution time	Memory
73456		SmsS	Ancient Books (IOI17_books)	C++14	0 / 100	4 ms	684 KiB

books

#include<bits/stdc++.h>
using namespace std;
#define for2(a,b,c) for(int a = b; a < c; a++)
#include "books.h"
#define ll long long

const int maxn =  1000100;
int par[maxn];
bool seen[maxn];
int getpar(int x){
	if(par[x] < 0) return x;
	return par[x] = getpar(par[x]);
}

long long minimum_walk(std::vector<int> p, int s) {
	ll res = 0;
	int n = p.size();
	fill(par,par+n,-1);
	for2(i,0,n) res += abs(i-p[i]);
	for2(rep,0,n){
		int i = (rep+s)%n;
		if(seen[i]) continue;
		int l = min(i,p[i]);
		int r = max(i,p[i]);
		bool SS = 0;
		int L = i;
		int R = i;
		seen[i] = 1;
		while(1){
			int j = -1;
			if(L != l){
				L--;
				j = L;
			}
			if(R != r){
				R++;
				j = R;
			}

			if( j == -1) break;
			seen[j] = 1;
			L = min(L,p[j]);
			R = max(R,p[j]);
			int x = getpar(i);
			int y = getpar(j);
			if(x == getpar(s) || y == getpar(s)) SS=1;
			if(x != y){
				if(par[x] < par[y]) swap(x,y);
				par[y] += par[x];
				par[x] = y;
			}
		}
		if(SS && rep) res += 2;
	}
	for2(i,0,n) if(getpar(i) == i) res += 2;
	res -= 2;
	for(int i = n-1; i > s; i--){
		if(par[getpar(i)] != -1) break;
		res -= 2;
	}
	for2(i,0,n){
		if(par[getpar(i)] != -1 || i == s) break;
		res -= 2;
	}
	return res;
}

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