#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100'000;
using ll = long long;
int aib[MAXN + 1];
int n;
map<int, queue<int>> pos;
int target[MAXN + 1];
int viz[MAXN + 1];
void update( int pos, int val ) {
for( int i = pos; i <= n; i += i & ( -i ) )
aib[i] += val;
}
ll query( int pos ) {
ll s = 0;
for( int i = pos; i > 0; i -= i & ( -i ) )
s += aib[i];
return s;
}
long long count_swaps( vector<int> v ) {
int i, current;
ll scor;
n = v.size();
for( i = 0; i < n; i++ )
pos[v[i]].push(i);
current = 0;
for( i = 0; i < n; i++ ) {
if( !viz[i] ) {
int shoe_size = v[i];
int pair_size = -v[i];
int pos1 = i;
int pos2 = pos[pair_size].front();
pos[shoe_size].pop();
pos[pair_size].pop();
viz[pos1] = viz[pos2] = 1;
if( shoe_size < 0 ) {
target[pos1] = current++;
target[pos2] = current++;
} else {
target[pos2] = current++;
target[pos1] = current++;
}
}
}
for( i = 1; i <= n; i++ )
aib[i] = 1;
scor = 0;
for( i = 0; i < n; i++ ) {
scor += query( target[i] );
update( target[i], -1 );
}
return scor;
}
