#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];
int BIT[1 + 2 * MAX_N];
void addValue(int index, int addValue) {
index++;
for (int i = index; i <= 2 * MAX_N; i += i&-i) {
BIT[i] += addValue;
}
//printf("addValue(%d, %d)\n", index - 1, addValue);
}
int prefixSum(int index) {
index++;
int answer = 0;
for (int i = index; i > 0; i -= i&-i) {
answer += BIT[i];
}
//printf("prefixSum(%d) -> %d\n", index - 1, answer);
return answer;
}
void pairUp(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 {
pairUp(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++) {
addValue(i, +1);
}
for (int i = 0; i < 2 * n; i++) {
if (i < pair[i]) {
addValue(i, -1);
addValue(pair[i], -1);
answer += prefixSum(pair[i]);
if (s[i] > 0) {
answer++;
}
}
//printf("%lld ", answer);
}
return answer;
}
