#include<bits/stdc++.h> using namespace std; #include "shoes.h" long long count_swaps(std::vector<int> s) { int n = s.size()/2; set<int> se; for(int i=0;i<n;i++){ se.insert(abs(s[i])); } if(n%2==0) return n/2; else{ return n/2 + se.size()-1; } }