Submission #283743

#	Time	Username	Problem	Language	Result	Execution time	Memory
283743		hank55663	Ancient Books (IOI17_books)	C++14	50 / 100	277 ms	22124 KiB

books

#include "books.h"
#include<bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define pb push_back
#define mp make_pair
#define x first
#define y second
int f[1000005];
int l[1000005];
int r[1000005];
int Find(int x){
	if(f[x]==x)return x;
	return f[x]=Find(f[x]);
}
int pre[1000005];
long long minimum_walk(std::vector<int> p, int s) {
//	vector<pii> v;
	long long ans=0;
	int Min=1e9;
	int over=0;
	for(int i = 0;i<p.size();i++){
		if(p[i]!=i){
//			v.pb(mp(p[i],i));
			ans+=abs(p[i]-i);
			Min=min(Min,abs(i-s));
			if((i<s&&p[i]>s)||(i>s&&p[i]<s))over=1;
		}
		l[i]=1e9;
		r[i]=0;
		f[i]=i;
	}
	for(int i = 0;i<p.size();i++){
		f[Find(p[i])]=Find(i);
	}
	for(int i = 0;i<p.size();i++){
		l[Find(i)]=min(l[Find(i)],i);
		r[Find(i)]=max(r[Find(i)],i);
	}
	vector<pii> v;
	for(int i = 0;i<p.size();i++){
		if(f[i]==i&&l[i]!=r[i]){
			v.pb(mp(l[i],r[i]));
		}
	}
	if(v.empty())return 0;
	sort(v.begin(),v.end());
	int Max=v[0].x;
	for(auto it:v){
		ans+=max(0,(it.x-Max)*2);
		Max=max(Max,it.y);	
	}
	if(!over){
		if(s>Max||s<v[0].x){
			
			Min=max(s-Max,v[0].x-s);
		}
		else{
			Min=0;
		}
	}
	return ans+Min*2;
}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:22:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |  for(int i = 0;i<p.size();i++){
      |                ~^~~~~~~~~
books.cpp:33:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |  for(int i = 0;i<p.size();i++){
      |                ~^~~~~~~~~
books.cpp:36:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |  for(int i = 0;i<p.size();i++){
      |                ~^~~~~~~~~
books.cpp:41:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |  for(int i = 0;i<p.size();i++){
      |                ~^~~~~~~~~

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