Submission #1730821

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Source Code Expand

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define fbo find_by_order
#define ook order_of_key
 
typedef long long ll;
typedef pair<ll,int> ii;
typedef vector<int> vi;
typedef long double ld; 
typedef tree<ii, null_type, less<ii>, rb_tree_tag, tree_order_statistics_node_update> pbds;
typedef set<int>::iterator sit;
typedef map<int,int>::iterator mit;
typedef vector<int>::iterator vit;

pbds pos,neg;
int timer;
ll len[100011];
ll shiftpos,shiftneg;

void addpos(ll x)
{
	pos.insert(mp(x-shiftpos,timer++));
}

void addneg(ll x)
{
	neg.insert(mp(x-shiftneg,timer++));
}

int main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	int n; cin>>n;
	ll m=0; ll c=0;
	for(int i=0;i<n;i++)
	{
		ll l,r; cin>>l>>r;
		len[i]=r-l;
		//last m elements increase by len[i-1];
		if(i>0)
		{
			shiftpos+=len[i-1];
			c-=len[i-1]*m;
		}
		//the rest decrease by len[i]
		shiftneg-=len[i];
		addpos(l); addpos(l);
		auto it=pos.begin();
		ll res=it->fi+shiftpos;
		pos.erase(pos.begin()); addneg(res);
		int neglas=prev(neg.end())->fi+shiftneg;
		int posles=pos.begin()->fi+shiftpos;
		if(!neg.empty()&&neglas>posles)
		{
			neg.erase(prev(neg.end())); pos.erase(pos.begin());
			addpos(neglas); addneg(posles);
		}
		m++; c-=l;
	}
	while(m>0)
	{
		c+=(*prev(pos.end())).fi+shiftpos;
		m--;
		pos.erase(prev(pos.end()));
	}
	cout<<c<<'\n';
}

Submission Info

Judge Result