Submission #355273

#	Time	Username	Problem	Language	Result	Execution time	Memory
355273		Kerim	Ancient Books (IOI17_books)	C++17	22 / 100	240 ms	18540 KiB

books

#include "books.h"
#include "bits/stdc++.h"
#define MAXN 100009
#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;}
const int N=1004;
int dp[N][N];
int L[MAXN],R[MAXN],bel[MAXN],S;
int destL,destR;
PII extend(int l,int r){
	int lp=l,rp=r;
	if(bel[l])lp=L[bel[l]];
	if(bel[r])rp=R[bel[r]];
	while(1){	
		if(l>lp){
			if(bel[--l])
				umin(lp,L[bel[l]]),umax(rp,R[bel[l]]);	
		}
		else if(r<rp){
			if(bel[++r])
				umin(lp,L[bel[r]]),umax(rp,R[bel[r]]);	
		}
		else
			break;
	}
	return mp(l,r);
}
int rec(int l,int r){
	//cout<<l<<" "<<r<<endl;
	if(l<destL or r>destR)return INF;
	PII tmp=extend(l,r);
	l=tmp.ff;r=tmp.ss;
	//printf("%d~%d\n",l,r);
	if(l==destL and r==destR)return 0;
	int &ret=dp[l][r];
	if(~ret)return ret;
	return ret=min(rec(l-1,r),rec(l,r+1))+2;
}
long long minimum_walk(vector<int> p, int s) {
	memset(dp,-1,sizeof dp);
	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: 0 / 28
• Subtask 4: 0 / 20
• Subtask 5: 0 / 30