Submission #486818

#	Time	Username	Problem	Language	Result	Execution time	Memory
486818		Haidara	Arranging Shoes (IOI19_shoes)	C++17	10 / 100	467 ms	1048580 KiB

shoes

#include<bits/stdc++.h>
#include<shoes.h>
#define rep(i,x,n) for(int i=(x);i<(n);i++)
#define FOR(i,n) rep(i,0,n)
#define v(i) vector< i >
#define ll long long 
using namespace std;
const ll inf=1LL<<62LL;
const ll mod=1e9+7;
const ll maxn=100200;
ll st[maxn];
int n;
int query(int ql,int qr,int l=1,int r=n,int inx=1)
{
	if(ql<=l&&r<=qr)
		return st[inx];
	if(ql>r||l>qr)
		return 0;
	int mid=l+(r-l)/2;
	return query(ql,qr,mid+1,r,inx*2+1)+query(ql,qr,l,mid,inx*2);
}
void update(int pos,int val=0,int l=1,int r=n,int inx=1)
{
	if(l==r)
	{
		st[inx]=val;
		return ;
	}
	int mid=l+(r-l)/2;
	if(mid<=pos)
		update(pos,val,l,mid,inx*2);
	else 
		update(pos,val,mid,r,inx*2+1);
	st[inx]=st[inx*2]+st[inx*2+1];
}
ll count_swaps(v(int)a)
{
	ll ans=0;
	n=a.size();
	FOR(i,n)
	update(i+1,1);
	set<int>posl[maxn],posr[maxn];
	FOR(i,n)
	if(a[i]<0)
		posl[-a[i]].insert(i);
	else 
		posr[a[i]].insert(i);
	v(bool)vis(maxn,0);
	FOR(i,n)
	{
		if(vis[i])
			continue;
		if(a[i]>0)
			ans++;
		a[i]=abs(a[i]);
		auto right=*posr[a[i]].begin();
		auto left=*posl[a[i]].begin();
		posl[a[i]].erase(posl[a[i]].begin());
		posr[a[i]].erase(posr[a[i]].begin());
		vis[right]=1;
		vis[left]=1;
		if(left>right)
			swap(left,right);
		ans+=query(left+1,1+right)-1;
		update(left+1);
		update(right+1);
	}
	return ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15