#include "shoes.h"
#include <set>
#include <cstdio>
#include <algorithm>
#define ll long long
#define mid ((tl + tr) / 2)
using namespace std;
ll n;
vector<ll> shoes(200000);
struct segtree {
segtree* left = NULL; segtree* right = NULL;
multiset<ll> here;
ll m_tl, m_tr;
void build(ll tl, ll tr) {
m_tl = tl, m_tr = tr;
if (tl == tr) {
here.insert(shoes[tl]);
return;
}
left = new segtree();
right = new segtree();
left->build(tl, mid);
right->build(mid + 1, tr);
merge(left->here.begin(), left->here.end(), right->here.begin(), right->here.end(),
inserter(here, here.begin()));
}
ll query(ll needle) {
here.erase(here.find(needle));
if (m_tl == m_tr) return m_tl;
if (left->here.find(needle) != left->here.end())
return left->query(needle);
else if (right->here.find(needle) != right->here.end())
return right->query(needle);
else puts("fuck this");
return 696969696969696969;
}
} segtree;
long long count_swaps(std::vector<int> s) {
ll n = s.size();
for (ll i = 0; i < n; ++i) shoes[i] = (ll)s[i];
segtree.build(0, n - 1);
ll active[n];
for (ll i = 0; i < n; ++i) active[i] = 1;
ll ans = 0;
for (ll i = 0; i < n; ++i) {
if (!active[i]) continue;
active[i] = 0;
segtree.query(shoes[i]);
ll nxt = -shoes[i];
ll q = segtree.query(nxt);
active[q] = 0;
ans += (q - i - 1);
if (nxt < 0) ++ans;
}
return ans;
}
