Submission #496513

#	Time	Username	Problem	Language	Result	Execution time	Memory
496513		PedroBigMan	Ancient Books (IOI17_books)	C++14	12 / 100	18 ms	27724 KiB

books

/*
Author of all code: Pedro BIGMAN Dias
Last edit: 15/02/2021
*/
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#pragma GCC optimize("Ofast")
#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <queue>
#include <deque>
#include <list>
#include <iomanip>
#include <stdlib.h>
#include <time.h>
#include <cstring>
#include "books.h"
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;
typedef long double ld;
#define REP(i,a,b) for(ll i=(ll) a; i<(ll) b; i++)
#define pb push_back
#define mp make_pair
#define pl pair<ll,ll>
#define ff first
#define ss second
#define whole(x) x.begin(),x.end()
#define DEBUG(i) cout<<"Pedro Is The Master "<<i<<endl
#define INF 500000000LL
#define EPS 0.00000001
#define pi 3.14159
#define VV(vvvv,NNNN,xxxx); REP(i,0,NNNN) {vvvv.pb(xxxx);}
ll mod=1000000007LL;

template<class A=ll> 
void Out(vector<A> a) {REP(i,0,a.size()) {cout<<a[i]<<" ";} cout<<endl;}

template<class A=ll>
void In(vector<A> &a, ll N) {A cur; REP(i,0,N) {cin>>cur; a.pb(cur);}} 


class ST
{
    public:
    ll N;
    
    class SV //seg value
    {
        public:
        ll a; 
        SV() {a=0LL;}
        SV(ll x) {a=x;}
        
        SV operator & (SV X) {SV ANS(a+X.a); return ANS;}
    };
      
    class LV //lazy value
    {
        public:
        ll a;
        LV() {a=0LL;}
        LV(ll x) {a=x;}
        
        LV operator & (LV X) {LV ANS(a+X.a); return ANS;}
    };
    
    SV upval(ll c) //how lazy values modify a seg value inside a node, c=current node
    {
        SV X(p[c].a+(range[c].ss-range[c].ff+1)*lazy[c].a);
        return X;
    }
    
    SV neuts; LV neutl;
    
    vector<SV> p;
    vector<LV> lazy;
    vector<pl> range;
    
    ST() {N=0LL;}
    ST(vector<ll> arr)
    {
        N = (ll) 1<<(ll) ceil(log2(arr.size()));
        REP(i,0,2*N) {range.pb(mp(0LL,0LL));}
        REP(i,0,N) {p.pb(neuts);}
        REP(i,0,arr.size()) {SV X(arr[i]); p.pb(X); range[i+N]=mp(i,i);}
        REP(i,arr.size(),N) {p.pb(neuts); range[i+N]=mp(i,i);}
        ll cur = N-1;
        while(cur>0)
        {
            p[cur]=p[2*cur]&p[2*cur+1];
            range[cur]=mp(range[2*cur].ff,range[2*cur+1].ss);
            cur--;
        }
        REP(i,0,2*N) {lazy.pb(neutl);}
    }
    
    void prop(ll c) //how lazy values propagate
    {
        lazy[2*c]=lazy[c]&lazy[2*c]; lazy[2*c+1]=lazy[c]&lazy[2*c+1];
        lazy[c]=neutl;
    }
    
    SV query(ll a,ll b, ll c=1LL) //range [a,b], current node. initially: query(a,b)
    {
        ll x=range[c].ff; ll y=range[c].ss;
        if(y<a || x>b) {return neuts;}
        if(x>=a && y<=b) {return upval(c);}
        prop(c);
		p[c]=upval(2*c)&upval(2*c+1);
        SV ans = query(a,b,2*c)&query(a,b,2*c+1);
        return ans;
    }
    
    void update(LV s, ll a, ll b, ll c=1LL) //update LV, range [a,b], current node, current range. initially: update(s,a,b)
    {
        ll x=range[c].ff; ll y=range[c].ss;
        if(y<a || x>b) {return ;}
        if(x>=a && y<=b) 
        {
            lazy[c]=s&lazy[c]; 
            return;
        }
		prop(c);
        update(s,a,b,2*c); update(s,a,b,2*c+1);
        p[c]=upval(2*c)&upval(2*c+1);
    }
};

vector<vector<ll> > CycleDecomp(vector<int> p) //cycle decomposition of permutation
{
	ll N = p.size(); vector<vector<ll> > ans; vector<ll> cur;
	vector<bool> visited; REP(i,0,N) {visited.pb(false);} 
	ll node;
	REP(i,0,N)
	{
		if(visited[i]) {continue;}
		node=i; cur.pb(node); node=p[node];
		while(node!=i)
		{
			cur.pb(node); node=p[node];
		}
		REP(i,0,cur.size()) {visited[cur[i]]=true;}
		ans.pb(cur);
		cur.clear();
	}
	return ans;
}

class WDiGraph
{
    public:
    ll N;
    vector<vector<pl> > adj; 
    vector<bool> visited;
    
    WDiGraph(vector<vector<pl> > ad)
    {
        adj=ad; N=adj.size(); REP(i,0,N) {visited.pb(false);}
    }
    
    vector<ll> BFS(ll s) 
    {
        vector<ll> distance; REP(i,0,N) {distance.pb(INF);}
        REP(i,0,N) {visited[i]=false;}
        distance[s]=0; visited[s]=true;
        deque<ll> d; d.pb(s); ll cur;
        while(!d.empty())
        {
            cur=d.front(); d.pop_front();
            REP(i,0,adj[cur].size())
            {
                if(!visited[adj[cur][i].ff]) 
                {
                    visited[adj[cur][i].ff]=true; 
                    d.pb(adj[cur][i].ff); 
                    distance[adj[cur][i].ff]=distance[cur]+1;
                }
            }
        }
        return distance;
    }
};

ll minimum_walk(vector<int> p, int s) 
{
	ll N = p.size();
	vector<vector<ll> > C = CycleDecomp(p);
	vector<pl> range;
	REP(i,0,C.size()) {range.pb({*min_element(whole(C[i])),*max_element(whole(C[i]))});}
	vector<ll> xx; VV(xx,N-1,0); ST S(xx);
	REP(i,0,range.size()) {if(range[i].ff==range[i].ss) {continue;} S.update(1,range[i].ff,range[i].ss-1);}
	vector<bool> in; VV(in,N-1,false);
	REP(i,0,N-1) {if(S.query(i,i).a>0) {in[i]=true;}}
	ll l=0,r=N-2; 
	while(l<s && !in[l]) {l++;}
	while(r>=s && !in[r]) {r--;}
	ll ans=0LL;
	REP(i,l,r+1) {if(!in[i]) {ans+=2LL;}}
	REP(i,0,N) {ans+=((ll) (abs(p[i]-i)));}
	ll T=s; while(T<N-1 && in[T]) {T++;} 
	ll SS;
	bool ok=false;
	REP(i,0,C.size()) {REP(j,0,C[i].size()) {if(C[i][j]==T) {T=i;ok=true;break;}} if(ok) {break;}}
	ok=false;
	REP(i,0,C.size()) {REP(j,0,C[i].size()) {if(C[i][j]==s) {SS=i;ok=true;break;}} if(ok) {break;}}
	REP(i,0,C.size()) {sort(whole(C[i]));}
	vector<vector<pl> > adj; VV(adj,C.size(),{});
	vector<ll>::iterator it;
	REP(i,0,C.size())
	{
		REP(j,0,C.size())
		{
			if(i==j) {continue;}
			it = lower_bound(whole(C[j]),range[i].ff);
			if(it!=C[j].end() && (*it)<=range[i].ss) {adj[i].pb({j,0LL}); continue;}
			ll dist=INF;
			if(it!=C[j].begin()) {it--; dist=min(dist,range[i].ff-*it);}
			it=upper_bound(whole(C[j]),range[i].ss);
			if(it!=C[j].end()) {dist=min(dist,*it - range[i].ss);}
			adj[i].pb({j,dist});
		
		}
	}
	WDiGraph G(adj); vector<ll> d = G.BFS(SS); ans+=2LL*d[T];
	return ans;
}

Compilation message (stderr)

books.cpp:5: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    5 | #pragma GCC optimization ("O3")
      | 
books.cpp:6: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    6 | #pragma GCC optimization ("unroll-loops")
      | 
books.cpp: In function 'll minimum_walk(std::vector<int>, int)':
books.cpp:232:42: warning: 'SS' may be used uninitialized in this function [-Wmaybe-uninitialized]
  232 |  WDiGraph G(adj); vector<ll> d = G.BFS(SS); ans+=2LL*d[T];
      |                                          ^

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