#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
struct ft {
int N; vector<int> tr;
ft(int N): N(N), tr(N+1,0) {}
int sum(int i) {
i++;
int ans = 0;
while (i > 0) {
ans += tr[i];
i -= i&-i;
}
return ans;
}
int sumR(int i, int j) {
return sum(j) - sum(i);
}
void add(int i, int x) {
i++;
while (i <= N) {
tr[i] += x;
i += i&-i;
}
}
};
long long count_swaps(std::vector<int> s) {
int n = s.size() / 2;
vector<vector<int>> posL(n+1), posR(n+1);
vector<int> R(2*n, -1);
for (int i = 0; i < 2*n; i++) {
if (s[i] > 0) posR[s[i]].push_back(i);
else posL[-s[i]].push_back(i);
}
long long ans = 0;
for (int j = 1; j <= n; j++) {
for (int k = 0; k < (int)posR[j].size(); k++) {
// cout << posL[j][k] << " " << posR[j][k] << "\n";
//ans += abs(posR[j][k] - posL[j][k]) - 1;
if (posR[j][k] < posL[j][k]) {
R[posR[j][k]] = posL[j][k];
ans++;
}
else R[posL[j][k]] = posR[j][k];
}
}
ft tree(2*n);
for (int i = 0; i < 2*n; i++) {
if (R[i] == -1) continue;
// cout << i << " " << R[i] << " " << tree.sum(1) << "\n";
ans += R[i] - i - 1 - tree.sumR(i,R[i]);
tree.add(R[i],1);
}
return ans;
}
