#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
const ll MOD = 998244353;
const ll INF = 1e18;
const ld EPS = 1e-12;
#define endl "\n"
#define sp <<" "<<
#define REP(i, a, b) for(ll i = a; i < b; i++)
#define dbg(x) cout << #x << " = " << x << endl
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define fast_io() ios_base::sync_with_stdio(false); cin.tie(NULL)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) ((ll)(x).size())
struct custom_hash {
static uint64_t splitmix64(uint64_t x) {
// http://xorshift.di.unimi.it/splitmix64.c
x += 0x9e3779b97f4a7c15;
x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
return x ^ (x >> 31);
}
size_t operator()(uint64_t x) const {
static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
return splitmix64(x + FIXED_RANDOM);
}
};
template <typename Key, typename Value>
using hash_map = unordered_map<Key, Value, custom_hash>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
// uniform_int_distribution<int>(a, b)(rng);
// shuffle(all(a), rng);
// https://www.geeksforgeeks.org/inversion-count-in-array-using-merge-sort/#expected-approach-using-merge-sort-onlog-n-time-and-on-space
// This function merges two sorted subarrays arr[l..m] and arr[m+1..r]
// and also counts inversions in the whole subarray arr[l..r]
ll countAndMerge(vector<int>& arr, int l, int m, int r) {
// Counts in two subarrays
int n1 = m - l + 1, n2 = r - m;
// Set up two vectors for left and right halves
vector<int> left(n1), right(n2);
for (int i = 0; i < n1; i++)
left[i] = arr[i + l];
for (int j = 0; j < n2; j++)
right[j] = arr[m + 1 + j];
// Initialize inversion count (or result) and merge two halves
ll res = 0;
int i = 0, j = 0, k = l;
while (i < n1 && j < n2) {
// No increment in inversion count if left[] has a
// smaller or equal element
if (left[i] <= right[j])
arr[k++] = left[i++];
// If right is smaller, then it is smaller than n1-i
// elements because left[] is sorted
else {
arr[k++] = right[j++];
res += (n1 - i);
}
}
// Merge remaining elements
while (i < n1)
arr[k++] = left[i++];
while (j < n2)
arr[k++] = right[j++];
return res;
}
// Function to count inversions in the array
ll countInv(vector<int>& arr, int l, int r){
ll res = 0;
if (l < r) {
int m = (r + l) / 2;
// Recursively count inversions in the left and
// right halves
res += countInv(arr, l, m);
res += countInv(arr, m + 1, r);
// Count inversions such that greater element is in
// the left half and smaller in the right half
res += countAndMerge(arr, l, m, r);
}
return res;
}
ll inversionCount(vector<int> &arr) {
int n = arr.size();
return countInv(arr, 0, n-1);
}
ll count_swaps(vector<int> s) {
int n = s.size();
// 2, 1, -1, -2
// 1, 2, -2, -1
map<int, vector<int>> pos;
REP(i, 0, n) {
pos[s[i]].push_back(i);
}
int id = 1;
for (auto &x : pos) {
if (x.first > 0) break;
int m = x.second.size();
REP(i, 0, m) {
s[x.second[i]] = -id;
s[pos[-x.first][i]] = id;
id++;
}
}
vector<int> dup(n);
map<int, int> have;
int curr = 1;
REP(i, 0, n) {
if (have[abs(s[i])] != 0) {
dup[i] = have[abs(s[i])] + (s[i] > 0);
have[abs(s[i])] = 0;
} else {
// cerr << i << endl;
dup[i] = curr + (s[i] > 0);
have[abs(s[i])] = curr;
curr += 2;
}
}
// REP(i, 0, n) {
// cerr << dup[i] << " ";
// } cerr << endl;
// return inversionCount(dup);
ll ans = inversionCount(dup);
// assert(ans >= 0 and ans <= (n * (n+1)) / 2);
return ans;
}
