#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int n;
ll count_swaps(vector<int> s) {
n = s.size() / 2;
ll minimum = 0;
vector<int> current_location(2*n, 0);
map<int, set<int>> shoes;
set<int> used;
for (int i = 0; i < 2*n; i++) {
shoes[s[i]].insert(i);
}
for (int i = 0; i < 2*n; i++) {
if (used.count(i)) continue;
int size = s[i];
int partner = *shoes[-size].begin();
used.insert(i); used.insert(partner);
shoes[size].erase(i); shoes[-size].erase(partner);
int dist = (current_location[partner] + partner) - (current_location[i] + i) - 1;
if (size > 0) dist++;
minimum += dist;
for (int k = i; k < 2*n; k++) current_location[k]++;
for (int k = partner; k < 2*n; k++) current_location[k]--;
}
return minimum;
}
