#include <bits/stdc++.h>
using namespace std;
int const N=2e5+5;
map<int,stack<int>> ind;
int n;
long long ans=0;
bool rem[N];
template<class TP> class SegmentTree{
private://cannot be access outside
//we can set constant here
int const DEFAULT = 0;
int const INF = 1e9;
//global varibles
vector<int> segtree;
int sz;
public:
//constructor and it should be 4 * n in top_down segtree
SegmentTree(int sz) : sz(sz), segtree(sz * 4, DEFAULT){};
//Now here all function we want your data to have
void recalculate(int node) {
segtree[node] = segtree[2 * node+1] + segtree[2 * node + 2];
}
void update(int node, int left, int right, int ind, int val) {
if (left == right) //we are in the indth leaf
segtree[node] = val;
else {
int middle = (left + right) / 2;
if (ind <= middle)//we need to update the left son
update(2 * node + 1, left, middle, ind, val);
else
update(2 * node + 2, middle + 1, right, ind, val);
//after updating said son, recalculate the current segment
recalculate(node);
}
}
int query(int node, int left, int right, int l, int r) {
if (l <= left && right <= r) {
//the segment of "node" is completely included in the query
return segtree[node];
}
else {
int answer = 0;
int middle = (left + right) / 2;
if (l <= middle) {
//the query segment and the left son segment have at least one element in common
answer += query(2 * node + 1, left, middle, l, r);
}
if (r > middle) {
//the query segment and the right son segment have at least one element in common
answer += query(2 * node + 2, middle + 1, right, l, r);
}
return answer;
}
}
};
long long count_swaps(vector<int> v){
n=v.size();
n/=2;
for (int i = (2*n)-1; i>=0; --i)
ind[v[i]].push(i);
SegmentTree<int> tree(2*n);
for (int i = 0; i < 2*n; ++i)
{
if(rem[i])
continue;
if(v[i]>0)
ans++;
ind[v[i]].pop();
rem[i]=1;
int op=v[i]*(-1);
int index=ind[op].top();
ind[op].pop();
rem[index]=1;
int swp=(index-i)-1;
swp-=tree.query(0,1,2*n,i+1,index);
ans+=swp;
tree.update(0,1,2*n,index+1,1);
}
return ans;
}
