Submission #355340

#	Time	Username	Problem	Language	Result	Execution time	Memory
355340		Kerim	Ancient Books (IOI17_books)	C++17	100 / 100	249 ms	77676 KiB

books

#include "books.h"
#include "bits/stdc++.h"
#define MAXN 1000009
#define INF 1000000007
#define mp(x,y) make_pair(x,y)
#define all(v) v.begin(),v.end()
#define pb(x) push_back(x)
#define wr cout<<"----------------"<<endl;
#define ppb() pop_back()
#define tr(ii,c) for(__typeof((c).begin()) ii=(c).begin();ii!=(c).end();ii++)
#define ff first
#define ss second
#define my_little_dodge 46
#define debug(x)  cerr<< #x <<" = "<< x<<endl;
using namespace std;

typedef long long ll;
typedef pair<int,int> PII;
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
int L[MAXN],R[MAXN],bel[MAXN],S;
int destL,destR;
void extend(int &l,int &r){
	int lp=l,rp=r;
	if(bel[l])umin(lp,L[bel[l]]),umax(rp,R[bel[l]]);
	if(bel[r])umin(lp,L[bel[r]]),umax(rp,R[bel[r]]);
	while(l!=lp or r!=rp){	
		if(l>lp and bel[--l])umin(lp,L[bel[l]]),umax(rp,R[bel[l]]);	
		if(r<rp and bel[++r])umin(lp,L[bel[r]]),umax(rp,R[bel[r]]);	
	}
}
int rec(int l,int r){
	extend(l,r);
	if(l==destL and r==destR)return 0;
	if(l==destL)return rec(l,r+1)+2;
	if(r==destR)return rec(l-1,r)+2;
	int fl=l-1,fr=r;extend(fl,fr);
	int el=l,er=r+1;extend(el,er);
	int ans_l=1,ans_r=1;
	while(fl!=destL and fr<er){
		ans_l++;fl--;
		extend(fl,fr);	
	}
	if(fr<er)return ans_l*2+rec(fl,fr);
	fl=l,fr=r+1;extend(fl,fr);
	el=l-1,er=r;extend(el,er);
	while(fr!=destR and fl>el){
		ans_r++;fr++;
		extend(fl,fr);
	}
	return min(ans_l,ans_r)*2+rec(fl,fr);
}
long long minimum_walk(vector<int> p, int s) {
	int n=int(p.size());vector<int>vis(n);
	destL=destR=s;ll res=0;
	for(int i=0;i<n;i++){
		res+=abs(p[i]-i);
		if(p[i]!=i and !vis[i]){
			int to=i;L[++S]=i;
			do{umax(R[S],to);bel[to]=S;vis[to]=1;to=p[to];}while(to!=i);
			umin(destL,L[S]);umax(destR,R[S]);
		} 
	}
	return rec(s,s)+res;
}

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