Submission #384800

#	Time	Username	Problem	Language	Result	Execution time	Memory
384800		kshitij_sodani	Ancient Books (IOI17_books)	C++14	50 / 100	527 ms	120404 KiB

books

//#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
typedef long long llo;
#define mp make_pair
#define pb push_back
#define a first 
#define b second
#define endl '\n'


#include "books.h"
llo ans=0;
llo n;
vector<llo> adj[1000001];
llo vis[1000001];
vector<llo> ss;
void dfs(int no){
	vis[no]=1;
	ss.pb(no);
	for(auto j:adj[no]){
		if(vis[j]==0){
			dfs(j);
		}
	}
}
long long minimum_walk(std::vector<int> p, int s) {
	while(p.size()){
		if(p.back()+1==p.size()){
			p.pop_back();
		}
		else{
			break;
		}
	}


	n=p.size();
//cout<<p.size()<<":"<<endl;
	if(n==0){
		return 0;
	}
	for(int i=0;i<n;i++){
		adj[i].pb(p[i]);
	}
	//llo co=0;
	llo ans=0;
	vector<pair<llo,llo>> tt;
	for(int i=0;i<n;i++){
		if(vis[i]==0){
			ss.clear();
			dfs(i);
			/*if(ss.size()==0){
				continue;
			}*/
			llo mi=ss[0];
			llo ma=ss[0];
			for(auto j:ss){
				mi=min(mi,j);
				ma=max(ma,j);
			}
			tt.pb({mi,ma});
			//co++;
			
			for(int j=0;j+1<ss.size();j++){
				ans+=abs(ss[j]-ss[j+1]);
			}
		/*	for(auto j:ss){
				cout<<j<<",,";
			}
			cout<<endl;*/
			ans+=(abs(ss[0]-ss.back()));
		}
	}
	sort(tt.begin(),tt.end());
	vector<pair<llo,llo>> tt2;
	for(auto j:tt){
		if(tt2.size()==0){
			tt2.pb(j);
		}
		else{
			if(tt2.back().b<j.a){
				tt2.pb(j);
			}
			else{
				tt2[tt2.size()-1].b=max(tt2[tt2.size()-1].b,j.b);
			}
		}
	}
	llo xx=tt2.size();
	ans+=2*(xx-1);


	//ans+=2*(co-1);

	return ans;
}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:29:16: warning: comparison of integer expressions of different signedness: '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |   if(p.back()+1==p.size()){
      |      ~~~~~~~~~~^~~~~~~~~~
books.cpp:65:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |    for(int j=0;j+1<ss.size();j++){
      |                ~~~^~~~~~~~~~

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