#include "shoes.h" #include <bits/stdc++.h> using namespace std; typedef long long ll; typedef pair<int, int> pii; typedef pair<ll, ll> pll; const int MAXN = 1e5; int S[MAXN+10], N; ll ans; bool vis[MAXN+10]; ll count_swaps(vector<int> _S) { int i, j; N=_S.size()/2; for(i=1; i<=2*N; i++) S[i]=_S[i-1]; for(i=1; i<=2*N; i++) { if(vis[i]) continue; for(j=i+1; j<=2*N; j++) { if(vis[j]) continue; if(S[j]==-S[i]) break; ans++; } vis[i]=true; vis[j]=true; if(S[j]<S[i]) ans++; } return ans; }