Submission #757872

#	Time	Username	Problem	Language	Result	Execution time	Memory
757872		alexander707070	Ancient Books (IOI17_books)	C++14	0 / 100	2 ms	340 KiB

books

#include<bits/stdc++.h>
#define MAXN 1000007
using namespace std;
 
int n,perm[MAXN],br,cnt,last,maxpos,to[MAXN],curr;
bool li[MAXN];
long long sum,add[MAXN],ans;
 
void dfs(int x){
	li[x]=true; maxpos=max(maxpos,x);
	sum+=abs(x-perm[x]); br++;
	if(!li[perm[x]])dfs(perm[x]);
}
 
long long minimum_walk(vector<int> p, int s){
	n=int(p.size());
 
	for(int i=0;i<n;i++)perm[i]=p[i];
 
	for(int i=0;i<n;i++){
		if(!li[i]){
			sum=br=maxpos=0; 
			dfs(i); add[i]=sum;
			to[i]=maxpos;
			if(br>1)last=i;
		}
	}
	
	for(int i=0;i<=last;i++){
		ans+=add[i]; curr=max(curr,to[i]);
		if(i<last and i>=curr)ans++;
	}
	ans+=last;
 
	return ans;
}
 
/*
int main(){
	cout<<minimum_walk({0, 2, 3, 1}, 0)<<"\n";
}
*/

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