Problem: 2052A - Adrenaline Rush
Language: java

Solution 1 (runtime: 2124 ms):
import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] arr = new int[n];
        for(int i = 0; i < n ; i++) {
            arr[i] = sc.nextInt();
        }
        solve(n , arr);
    }
    static void solve(int n, int[] arr) {
        List<String> list = new ArrayList<>();
        for(int i = n-1; i >= 0; i--) {
            int maxElement = i+1;
            int index = 0;
            for(int j = 0; j < n; j++) {
                if(arr[j] == maxElement) {
                    index = j;
                    break;
                }
            }
            //take front
            for(int j = index; j >= 1; j--) {
                list.add(arr[j-1]+ " " + arr[j]);
                int temp = arr[j];
                arr[j] = arr[j-1];
                arr[j-1] = temp;
            }
            //take back
            for(int j = 0; j < i; j++) {
                list.add(arr[j]+ " " + arr[j+1]);
                int temp = arr[j];
                arr[j] = arr[j+1];
                arr[j+1] = temp;
            }
        }
        Collections.reverse(list);
        System.out.println(list.size());
        for(String s : list) {
            System.out.println(s);
        }
    }
}

Solution 2 (runtime: 1093 ms):

import java.io.*;
import java.util.*;

/**
 * Problem    = cf2052a
 * Date       = Mon Jan 27 23:11:17 PST 2025
 */
public class cf2052a {

  static class Pair {
    int x,y;
    Pair(int x, int y){
      this.x=x;this.y=y;
    }
  }

  public void run() {
    int n = in.nextInt();
    int[] p = new int[n+1];
    for(int i = 1; i <= n; ++i){
      p[i]=in.nextInt();
    }
    Set<Integer> s = new HashSet<>();
    
    var pairs = new LinkedList<Pair>();
    for(int i = 1; i <= n; ++i){
      for(int j = p[i]+1; j <= n; ++j){
        if (!s.contains(j)){
          pairs.add(new Pair(j,p[i]));
        }
      }
      for(int j = n; j > 0; j--){
        if (p[i]==j) continue;
        if (!s.contains(j)){
          pairs.add(new Pair(p[i],j));
        }
      }
      s.add(p[i]);
    }
    out.println(pairs.size());
    for(var pair : pairs)
      out.println(pair.x + " " + pair.y);
  }

  /////////////////////////////////////////////////////////////////////////////////
  static InputStream in(){try{if(file!=null)return new FileInputStream(file+".in");
  return System.in;}catch(Exception e){throw new RuntimeException(e);}}static
  OutputStream out(){try{if(file!=null)return new FileOutputStream(file+".out");
  return System.out;}catch(Exception e){throw new RuntimeException(e);}}IR in=new
  IR(in());PrintWriter out=new PrintWriter(out());void c(){out.close();}static
  class IR{BufferedReader r;StringTokenizer t=null;IR(InputStream s){r=new
  BufferedReader(new InputStreamReader(s),32768);}boolean p(){while(t==null||
  !t.hasMoreTokens()){try{String l=r.readLine();if(l==null)return false;t=new
  StringTokenizer(l);}catch(IOException e){throw new RuntimeException(e);}}return
  true;}boolean hasNext(){return p();}String next(){p();return t.nextToken();}int
  nextInt(){return Integer.parseInt(next());}long nextLong(){return Long.parseLong(
  next());}double nextDouble(){return Double.parseDouble(next());}}public static
  void main(String[]args){cf2052a t=new cf2052a();t.run();t.c();}
  /////////////////////////////////////////////////////////////////////////////////
  static String file;
}