#include "shoes.h" #include <bits/stdc++.h> using namespace std; long long count_swaps(vector<int> s) { int n = s.size() / 2; long long ans = 0; while (n) { map<int, int> mp; for (int i = n * 2 - 1; i >= 0; --i) mp[s[i]] = i; int x = 1e9; for (int i = 0; i < n * 2; ++i) { if (s[i] < 0) continue; x = min(x, mp[-s[i]] + i + (mp[-s[i]] > i) - 1); } ans += x; for (int i = 0; i < n * 2; ++i) { if (s[i] < 0) continue; if (x == mp[-s[i]] + i + (mp[-s[i]] > i) - 1) { s.erase(s.begin() + max(mp[-s[i]], i)); s.erase(s.begin() + min(i, mp[-s[i]])); break; } } } return ans; }