#include <bits/stdc++.h>
#include "shoes.h"
using namespace std;
const int neg = 1e5;
int seg[400505];
queue<int> pos[200005];
bool vis[200005];
void update(int l, int r, int x, int loc) {
if (l <= x && x<= r) {
//cout << l << " " << r << endl;
seg[loc]++;
if (l != r) {
int mid = (l + r) / 2;
update(l, mid, x, loc * 2);
update(mid + 1, r, x, loc * 2 + 1);
}
}
}
int query(int l, int r, int x, int y, int loc) {
//cout << l << " " << r << endl;
//cout << l << " " << r << endl;
if(x <= l && r <= y) {
return seg[loc];
}
if (l >= y || r <= x) {
return 0;
}
if (l != r) {
int mid = (l + r) / 2;
return query(l, mid, x, y, loc * 2) + query(mid + 1, r, x, y, loc * 2 + 1);
}
return 0;
}
long long count_swaps(std::vector<int> s) {
int n = s.size();
int ans = 0;
for(int i = 0; i < n; i++) {
pos[s[i] + neg].push(i + 1);
}
for(int i = 0; i < n; i++) {
if (vis[i + 1]) {
continue;
}
else {
//cout << "::" << i << endl;
int next = -s[i] + neg;
if (s[i] > 0) {
ans++;
}
//cout << s[i] << " " << next - neg << endl;
int r = pos[next].front();
//cout << r << endl;
pos[next].pop();
pos[s[i] + neg].pop();
vis[i + 1] = true;
vis[r] = true;
ans += (r - (i + 1) - 1) - query(1, n, i + 1, r, 1);
//cout << "---" << ans << endl;
update(1, n, r, 1);
}
}
return ans;
}
