# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
486812 | Haidara | Arranging Shoes (IOI19_shoes) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#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 pos,int l=1,int r=n,int inx=1)
{
if(l==r)
return st[inx];
int mid=l+(r-l)/2;
st[inx*2]+=st[inx];
st[inx*2+1]+=st[inx];
st[inx]=0;
if(pos<=mid)
return query(pos,l,mid,inx*2);
return query(pos,mid+1,r,inx*2+1);
}
void update(int ql,int qr,int l=1,int r=n,int inx=1)
{
if(ql<=l&&r<=qr){
st[inx]++;
return ;
}
if(ql>r||l>qr)
return ;
st[inx*2]+=st[inx];
st[inx*2+1]+=st[inx];
st[inx]=0;
int mid=l+(r-l)/2;
update(ql,qr,l,mid,inx*2);
update(ql,qr,mid+1,r,inx*2+1);
}
ll count_swaps(v(int)a)
{
ll ans=0;
n=a.size();
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+=(*right+query(*right+1)-*left-query(*left+1)-1);
update(*left+1+query(*left+1),*right+1+query(*right+1));
}
return ans;
}