Codeforces Round #542 [Alex Lopashev Thanks-Round] (Div. 2) B. Two Cakes(思维)

#include <bits/stdc++.h>
#define ll long long
using namespace std;
int n;
vector<int> v[100005];

int main()
{
  scanf("%d",&n);
  for(int i=1;i<=2*n;i++){
    int x;
    scanf("%d", &x);
    v[x].push_back(i);
  }
  int t1 = 1, t2 = 1;
  ll ans = 0;
  for(int i=1;i<=n;i++){
    int xx = abs(t1 - v[i][0]) + abs(t2 - v[i][1]);
    int yy = abs(t1 - v[i][1]) + abs(t2 - v[i][0]);
    ans += min(xx, yy);
    t1 = v[i][0];
    t2 = v[i][1];
    
  }
  printf("%lld\n", ans);
  return 0;
}