#include <bits/stdc++.h>
#include "shoes.h"
using namespace std;
#define sz(x) (int)x.size()
#define all(x) x.begin(),x.end()
const long long inf = 1e18 + 7;
struct SEGT{
vector < int > t;
int tree_size;
const int identity_element = 0;
int merge(int x , int y){
return x + y;
}
void init(int x){
tree_size = x+3;
t.assign(2*tree_size , identity_element);
}
void modify(int p, int value) { // set value at position p
for (t[p += tree_size] = value; p > 1; p >>= 1){
t[p>>1] = merge(t[p] , t[p^1]);
}
}
int query(int l, int r) { // sum on interval [l, r]
int res = identity_element;
for (r+=1 , l += tree_size, r += tree_size; l < r; l >>= 1, r >>= 1) {
if (l&1) res = merge(res , t[l++]);
if (r&1) res = merge(res , t[--r]);
}
return res;
}
};
long long count_swaps(vector<int> s) {
int n = sz(s) / 2;
long long ans = 0;
SEGT segt;
segt.init(2 * n + 5);
int sayac0 = 1 , sayac1 = 2;
for(int i = 0;i<2*n;i++){
if(s[i] < 0){
ans += segt.query(sayac0 , 2*n);
segt.modify(sayac0 , 1);
sayac0+=2;
}
else{
ans += segt.query(sayac1 , 2*n);
segt.modify(sayac1 , 1);
sayac1+=2;
}
}
return ans;
}
