Submission #165312

#	Time	Username	Problem	Language	Result	Execution time	Memory
165312		Segtree	Ancient Books (IOI17_books)	C++14	50 / 100	200 ms	16868 KiB

books

#include<iostream>
#include<algorithm>
#include<vector>
#include"books.h"
using namespace std;
typedef long long ll;
#define chmin(a,b) a=min(a,b)
#define chmax(a,b) a=max(a,b)
#define N 1000010
ll minimum_walk(vector<int> p,int s){
    int n=p.size();
    ll sum=0;
    for(int i=0;i<n;i++)sum+=abs(i-p[i]);
    if(sum==0)return 0;
    bool vis[N];
    for(int i=0;i<n;i++)vis[i]=0;
    vector<pair<int,int> >v,nv;
    bool th=0;
    for(int i=0;i<n;i++){
	if(vis[i])continue;
	ll x=i;
	ll mi=1e17,ma=-1e17;
	while(1){
	    chmin(mi,x);
	    chmax(ma,x);
	    vis[x]=1;
	    x=p[x];
	    if(x==i)break;
	}
	if(mi!=ma){
	    v.push_back(make_pair(mi,ma));
	    if(mi<=s&&s<=ma)th=1;
	}
    }
    if(th==0)v.push_back(make_pair(s,s));
    sort(v.begin(),v.end());
    int rnd=-1;
    for(int i=0;i<v.size();i++){
	if(rnd<v[i].second){
	    nv.push_back(v[i]);
	    rnd=v[i].second;
	}
    }
    v=nv;
    
    if(th==1){
	int mi=1e9;
	for(int i=0;i<v.size();i++){
	    chmin(mi,abs(s-v[i].first));
	    chmin(mi,abs(s-v[i].second));
	}
	if(mi==1e9)return 0;
	//if(mi==0)cout<<1/0<<endl;
	sum+=mi*2;
    }
    
    ll bef=v[0].first;
    rnd=-1;
    for(int i=0;i<v.size();i++){
	if(~rnd&&rnd<v[i].first){
	    nv.push_back(make_pair(bef,rnd));
	    bef=v[i].first;
	    sum+=2*(v[i].first-rnd);
	}
	chmax(rnd,v[i].second);
    }
    nv.push_back(make_pair(bef,rnd));
    v=nv;
    return sum;
}

Compilation message (stderr)

books.cpp: In function 'll minimum_walk(std::vector<int>, int)':
books.cpp:38:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<v.size();i++){
                 ~^~~~~~~~~
books.cpp:48:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<v.size();i++){
              ~^~~~~~~~~
books.cpp:59:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<v.size();i++){
                 ~^~~~~~~~~

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