#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll , ll> ii;
#define ff first
#define ss second
#define pb push_back
#define in insert
const ll N = 2e5 + 5;
struct fenwick{
ll ft[N];
void build(){
memset(ft, 0 ,sizeof(ft));
return;
}
void up(ll p, ll x) {
for(; p < N; p += p & -p)
ft[p] += x;
}
ll sum(ll l, ll r) {
if(r < l) return 0;
ll ret = 0;
for(--l; l > 0; l -= l & -l) ret -= ft[l];
for(; r > 0; r -= r & -r) ret += ft[r];
return ret;
}
};
ll a[N];
vector < ll > v0[N], v1[N];
long long count_swaps(std::vector<int> s) {
ll n = s.size() / 2;
fenwick T; T.build();
for(ll i = 1; i <= 2*n; i++){
a[i] = s[i - 1];
T.up(i, 1);
if(a[i] < 0) v0[-a[i]].pb(i);
else v1[a[i]].pb(i);
}
for(ll i = n; i >= 1; i--){
reverse(v1[i].begin(), v1[i].end());
reverse(v0[i].begin(), v0[i].end());
}
ll ans = 0;
for(ll i = 1; i <= 2*n; i++){
if(T.sum(i, i) == 0) continue;
ll S = abs(a[i]);
ll st[2] = {v0[S].back(), v1[S].back()};
T.up(st[0], -1);
T.up(st[1], -1);
ans += T.sum(i, st[0]) + T.sum(i, st[1]) + (st[1] < st[0]);
v0[S].pop_back();
v1[S].pop_back();
}
return ans;
}
