#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
template<class T, class U>
void ckmin(T &a, U b)
{
if (a > b) a = b;
}
template<class T, class U>
void ckmax(T &a, U b)
{
if (a < b) a = b;
}
#define MP make_pair
#define PB push_back
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define FOR(i, a, b) for (auto i = (a); i < (b); i++)
#define FORD(i, a, b) for (auto i = (a) - 1; i >= (b); i--)
#define SZ(x) ((int) (x).size())
#define ALL(x) (x).begin(), (x).end()
#define MAXN 200013
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpi;
typedef vector<pll> vpl;
int N;
vi arr;
vi lt[MAXN], rt[MAXN];
vpi pos;
int A[MAXN];
ll fen[MAXN];
ll ans;
bool cmp(pii a, pii b)
{
return a.fi + a.se < b.fi + b.se;
}
void update(int idx, ll v)
{
for (int e = idx + 1; e <= 2 * N; e += e & (-e)) fen[e] += v;
}
ll query(int idx)
{
ll res = 0;
for (int e = idx + 1; e; e -= e & (-e)) res += fen[e];
return res;
}
ll count_swaps(vi a)
{
arr = a;
N = SZ(arr) >> 1;
FOR(i, 0, 2 * N)
{
if (arr[i] < 0) lt[-arr[i]].PB(i);
else rt[arr[i]].PB(i);
}
// cerr << "HUH\n";
FOR(i, 0, N + 1)
{
FOR(j, 0, SZ(lt[i]))
{
pos.PB({lt[i][j], rt[i][j]});
}
}
//agh look at subsequences
//ok you sort the pairs based on where they should go
//it breaks down into counting inversions of some stupid array, after you know where everythibng should go.
// cerr << "HI\n";
sort(ALL(pos), cmp);
FOR(i, 0, N)
{
A[2 * i] = pos[i].fi;
A[2 * i + 1] = pos[i].se;
}
FOR(i, 0, 2 * N)
{
ans += (i - query(A[i]));
update(A[i], 1);
}
return ans;
}
