#include "shoes.h" #include <bits/stdc++.h> using namespace std; long long count_swaps(vector<int> s) { int n=s.size(); vector<int> cnt[(int)2*n+5]; vector<int> used(2*n+5, 0); vector<bool> visited(2*n+5, false); long long comp=0; for (int i = 0; i < n; ++i) { cnt[s[i]+n].push_back(i); } for (int i = 0; i < n; ++i) { if (visited[i]) continue; int recherche=(-1*s[i])+n; if (s[i]<0) comp--; //cout << recherche << " " << n << " "; comp+=cnt[recherche][used[recherche]]-i; //cout << cnt[recherche][used[recherche]] << endl; visited[cnt[recherche][used[recherche]]]=true; used[recherche]++; used[s[i]+n]++; } cout << endl; return comp; }