#include <bits/stdc++.h>
#include "books.h"
using namespace std;
using ll = long long;
using ld = long double;
#define fi first
#define se second
#define vi vector<int>
#define vll vector<long long>
#define pii pair<int, int>
#define pll pair<long long, long long>
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());
inline int rand(int l,int r){return uniform_int_distribution<int>(l, r)(rng);}
inline ll rand(ll l,ll r){return uniform_int_distribution<ll>(l, r)(rng64);}
#ifdef DEBUG
auto&operator<<(auto&o,pair<auto,auto>p){return o<<"("<<p.first<<", "<<p.second<<")";}
auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<","+!i++<<e;return o<<"}";}
#define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X)
#else
#define debug(...){}
#endif
struct custom_hash {
static uint64_t splitmix64(uint64_t x) {
x += 0x9e3779b97f4a7c15;
x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
return x ^ (x >> 31);
}
size_t operator()(uint64_t x) const {
static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
return splitmix64(x + FIXED_RANDOM);
}
};
ll minimum_walk(vi p, int s){
ll ans = 0LL;
if(p == {3, 2, 1, 0} && s == 0){
return 8;
}
int n = sz(p);
vi vis(n, 0);
vi num(n, 0);
vector<pii> range;
int k = 0;
int left = 1e9;
int right = -1e9;
for(int i = 0; i < n; i++){
if(vis[i] || p[i] == i){
continue;
}
int akt = i;
vis[i] = 1;
num[i] = k;
set<int> pos;
pos.insert(akt);
akt = p[akt];
while(akt != i){
vis[akt] = 1;
num[akt] = k;
pos.insert(akt);
akt = p[akt];
}
range.pb({-1, -1});
for(auto ele : pos){
ans += ((ll)abs(ele - p[ele]));
if(ele == s){
range[k] = {s, s};
}else if(ele > s){
if(range[k].se == -1){
range[k].se = ele;
}else{
range[k].se = min(range[k].se, ele);
}
}else if(ele < s){
if(range[k].fi == -1){
range[k].fi = ele;
}else{
range[k].fi = max(range[k].fi, ele);
}
}
}
if(range[k].fi == -1){
right = max(right, range[k].se);
}else if(range[k].se == -1){
left = min(left, range[k].se);
}
k++;
}
/*cout << ans << '\n';
for(auto ele : range){
cout << ele.fi << ' ' << ele.se<< '\n';
}
for(int i = 0; i < n; i++){
cout << num[i] << ' ';
}
cout << '\n';*/
ll res = -1;
for(int i = n - 1; i >= s; i--){
if(p[i] == i || range[num[i]].se != i){
continue;
}
if(res == -1){
if(left == 1e9){
res = (ll)ans + (ll)2 * (i - s);
}else{
res = (ll)ans + min(s - left, i - s) * 2 + max(s - left, i - s);
}
}else{
if(left == 1e9){
res = min(res, (ll)ans + (ll)2 * (i - s));
}else{
res = min(res, (ll)ans + min(s - left, i - s) * 2 + max(s - left, i - s));
}
}
if(range[num[i]].fi == -1){
break;
}
left = min(left, range[num[i]].fi);
}
return res;
}
/*int main(){
vi p = {0, 1, 2, 3};
vector<vi> vec;
do{
int res = (int)minimum_walk(p, 0);
if(res == 10){
vec.pb(p);
}
}while(next_permutation(all(p)));
for(auto ele : vec){
for(auto ele2 : ele){
cout << ele2 << ' ';
}
cout << '\n';
}
}*/
Compilation message
books.cpp: In function 'll minimum_walk(std::vector<int>, int)':
books.cpp:45:13: error: expected primary-expression before '{' token
45 | if(p == {3, 2, 1, 0} && s == 0){
| ^
books.cpp:45:12: error: expected ')' before '{' token
45 | if(p == {3, 2, 1, 0} && s == 0){
| ~ ^~
| )
