Submission #758026

#	Time	Username	Problem	Language	Result	Execution time	Memory
758026		alexander707070	Ancient Books (IOI17_books)	C++14	50 / 100	486 ms	29684 KiB

books

#include<bits/stdc++.h>
#define MAXN 1000007
using namespace std;
 
int n,perm[MAXN],br,cnt,last,maxpos,to[MAXN],curr,pos;
bool li[MAXN],ok,used[MAXN];
long long sum,add[MAXN],ans;

bool tree[4*MAXN];

void update(int v,int l,int r,int ll,int rr){
	if(ll>rr)return;
	if(l==ll and r==rr){
		tree[v]=true;
	}else{
		int tt=(l+r)/2;
		update(2*v,l,tt,ll,min(tt,rr));
		update(2*v+1,tt+1,r,max(tt+1,ll),rr);
	}
}

bool getpos(int v,int l,int r,int pos){
	if(l==r)return tree[v];
	int tt=(l+r)/2;
	if(pos<=tt)return getpos(2*v,l,tt,pos) or tree[v];
	else return getpos(2*v+1,tt+1,r,pos)  or tree[v];
}
 
void dfs(int x){
	li[x]=true; 
	sum+=abs(x-perm[x]); br++;

	update(1,0,n-1,min(x,perm[x]),max(x,perm[x])-1);

	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=0; 
			dfs(i); add[i]=sum;
			if(br>1)last=i;
		}
	}

	for(int i=0;i<=last;i++){
		ans+=add[i];
		if(!getpos(1,0,n-1,i) and i<last)ans+=2;
	}

	return ans;
}
 
/*
int main(){
	cout<<minimum_walk({0,2,3,1}, 0)<<"\n";
}
*/

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