#include <bits/stdc++.h>
#include "books.h"
using namespace std;
#define pb push_back
#define st first
#define nd second
typedef long long ll;
typedef long double ld;
const ll I = 1000'000'000'000'000'000LL;
const int II = 2'000'000'000;
const ll M = 1000'000'007LL;
const int N = 1000'007;
bool vis[N];
int tab[N], rp[N], lp[N];
vector<pair<int, int>> inter;
int dis[N];
int DoDis(int n, int s)
{
int l, r, nl, nr, nd;
l = s; r = s;
for(int i = 0; i < n; ++i) dis[i] = II;
dis[s] = 0;
nd = 0;
nl = lp[s]; nr = rp[s];
while(l != nl || r != nr)
{
l = max(l - 1, nl); r = min(r + 1, nr);
dis[l] = min(dis[l], nd); dis[r] = min(dis[r], nd);
nl = min(nl, min(lp[r], lp[l])); nr = max(nr, max(rp[r], rp[l]));
}
while(l != 0 || r != n - 1)
{
//cerr << "R: " << l << " " << r << "\n";
nd = max(dis[l], dis[r]) + 1;
nl = max(0, l - 1); nr = min(n - 1, r + 1);
while(l != nl || r != nr)
{
l = max(l - 1, nl); r = min(r + 1, nr);
dis[l] = min(dis[l], nd); dis[r] = min(dis[r], nd);
nl = min(nl, min(lp[r], lp[l])); nr = max(nr, max(rp[r], rp[l]));
}
}
int ans = 0;
for(int i = 0; i < (int)inter.size(); ++i)
if(inter[i].nd >= s)
{
ans = dis[inter[i].st];
break;
}
//cerr << "D: " << ans << "\n";
return ans;
}
int Dl(int s)
{
for(int i = s - 1; i >= 0; --i)
if(tab[i] != i)
return s - i;
return 0;
}
int Dr(int s, int n)
{
for(int i = s + 1; i < n; ++i)
if(tab[i] != i)
return i - s;
return 0;
}
ll minimum_walk(vector<int> _p, int _s)
{
int n = (int)_p.size();
ll ans = 0LL;
for(int i = 0; i < n; ++i)
{
rp[i] = i; lp[i] = i;
tab[i] = _p[i];
}
bool czy = 0;
for(int i = 0; i < n; ++i)
{
ans += (int)abs(tab[i] - i);
if(vis[i]) continue;
int l = i, r = i, v = i;
vector<int> cur;
while(!vis[v])
{
cur.pb(v);
vis[v] = 1;
l = min(l, v); r = max(r, v);
v = tab[v];
}
//cerr << "FR: " << l << " " << r << "\n";
for(int j = 0; j < (int)cur.size(); ++j)
{rp[cur[j]] = r; lp[cur[j]] = l;}
if(l != r)
inter.pb(make_pair(l, r));
if(l != r && l <= _s && r >= _s)
czy = 1;
}
sort(inter.begin(), inter.end());
if(czy)
ans += DoDis(n, _s) * 2;
else
{
int dl = Dl(_s), dr = Dr(_s, n);
if(dl == 0 || dr == 0)
ans += (ll)(dl + dr) * 2LL;
}
int cur = 0;
for(int i = 0; i < (int)inter.size(); ++i)
{
if(i != 0 && cur < inter[i].st) ans += 2LL * (ll)(inter[i].st - cur);
cur = max(cur, inter[i].nd);
}
return ans;
}
