#include <bits/stdc++.h>
#include "books.h"
using namespace std;
const int MX = 1e6 + 100;
int mn[MX], mx[MX];
long long minimum_walk(vector<int> p, int s) {
int n = p.size(), t = 0;
for(int i = 0; i < n; i ++) mn[i] = i;
while(p[n - 1] == n - 1 and n - 1 > s) n --;
while(p[t ] == t and t < s) t ++;
long long sum = 0;
auto update = [&] (int s, int p) {
mx[s] = max(mx[s], mx[p]);
mn[s] = min(mn[s], mn[p]);
};
for(int i = t; i < n; i ++) {
mx[p[i]] = max(mx[p[i]], i);
mn[p[i]] = min(mn[p[i]], i);
mx[i] = max(mx[i], p[i]);
mn[i] = min(mn[i], p[i]);
sum += abs(i - p[i]);
}
queue<int> l, r;
for(int i = s - 1; i >= t; i --) l.push(i);
for(int i = s + 1; i < n; i ++) r.push(i);
srand(time(0));
while(1) {
if(l.size() and l.front() >= mn[s]) update(s, l.front()), l.pop();
else if(r.size() and r.front() <= mx[s]) update(s, r.front()), r.pop();
else if(l.size() and r.size() and rand() % 2) {
sum += 2;
update(s, r.front()), r.pop();
}
else if(l.size()) sum += 2, update(s, l.front()), l.pop();
else if(r.size()) sum += 2, update(s, r.front()), r.pop();
else break;
}
return sum;
}
//main () {
// cout << minimum_walk({2, 3, 0, 1}, 0);
//}
