Submission #953091

#	Time	Username	Problem	Language	Result	Execution time	Memory
953091		waldi	Ancient Books (IOI17_books)	C++17	50 / 100	371 ms	96492 KiB

books

#include "books.h"
#include <bits/stdc++.h>
#define FOR(i,p,k) for(int i=(p);i<=(k);++i)
#define REP(i,n) FOR(i,0,(n)-1)
#define ssize(x) (int((x).size()))
#define all(x) (x).begin(),(x).end()
using namespace std;
typedef long long ll;

ll minimum_walk(vector<int> perm, int start){
	int n = ssize(perm);
	ll wyn = 0ll;
	REP(i, n) wyn += abs(i-perm[i]);
	
	set<int> ciekawe;
	REP(i, n) if(perm[i] != i) ciekawe.emplace(i);
	
	vector<vector<int>> cykle;
	vector<int> lewo, prawo;
	vector<int> odw(n, -1);
	REP(i, n) if(odw[i] < 0){
		int mini = i, maks = i;
		vector<int> vec;
		for(int w = i; odw[w] < 0; w = perm[w]){
			odw[w] = ssize(cykle);
			vec.emplace_back(w);
			mini = min(mini, w);
			maks = max(maks, w);
		}
		cykle.emplace_back(vec);
		lewo.emplace_back(mini);
		prawo.emplace_back(maks);
	}
	
	//~ REP(i, n) printf("%d ", odw[i]);
	//~ printf("\n");
	//~ for(vector<int> t : cykle){
		//~ for(int i : t) printf("%d ", i);
		//~ printf("\n");
	//~ }
	
	int l = start, p = start;
	while(ssize(ciekawe)){
		auto it = ciekawe.lower_bound(l);
		if(it != ciekawe.end() && *it <= p){
			l = min(l, lewo[odw[*it]]);
			p = max(p, prawo[odw[*it]]);
			ciekawe.erase(it);
			continue;
		}
		int nast = it!=ciekawe.end() ? *it : n;
		int pop = it!=ciekawe.begin() ? *prev(it) : -1;
		if(nast==n || (pop>=0 && l-pop <= nast-p)) wyn += (l-pop)<<1, l = pop;
		else wyn += (nast-p)<<1, p = nast;
	}
	return wyn;
}

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