#include "shoes.h"
#include <math.h>
#include <stdio.h>
#include <queue>
const int MAX_N = 100000;
std::queue<int> indexes[1 + MAX_N];
int pair[2 * MAX_N];
bool active[2 * MAX_N];
void pair_up(int i, int j) {
pair[i] = j;
pair[j] = i;
}
long long count_swaps(std::vector<int> s) {
int n = (int)s.size() / 2;
for (int i = 0; i < 2 * n; i++) {
int value = abs(s[i]);
if (indexes[value].empty() || s[indexes[value].front()] == s[i]) {
indexes[value].push(i);
} else {
pair_up(i, indexes[value].front());
indexes[value].pop();
}
}
/*
printf("%d: ", n);
for (int i = 0; i < 2 * n; i++) {
printf("%d ", pair[i]);
}
printf("\n");//*/
long long answer = 0;
for (int i = 0; i < 2 * n; i++) {
active[i] = true;
}
for (int i = 0; i < 2 * n; i++) {
if (active[i]) {
for (int j = i + 1; j < pair[i]; j++) {
if (active[j]) {
answer++;
}
}
if (s[i] > 0) {
answer++;
}
active[i] = false;
active[pair[i]] = false;
}
}
return answer;
}
