Problem: 2052A - Adrenaline Rush
Language: java

Solution 1 (runtime: 546 ms):
#include<bits/stdc++.h>
#define LOCAL
#ifdef LOCAL
#if __has_include("C:\Users\HP\Desktop\Codeforces\template.cpp")
#include "C:\Users\HP\Desktop\Codeforces\template.cpp"
#else
#pragma message("template.cpp not found. Proceeding without it.")
#endif
#else
#define debug(...)
#endif
using namespace std;
#define out(x) cout<<x<<endl
#define in(x)  cin>>x
#define yes cout<<"YES"<<endl
#define no cout<<"NO"<<endl
#define int long long
#define pb(x) push_back(x)
#define all(x) x.begin(),x.end()
#define deb(x) cout<<"#"<<x<<endl
#define deb2(x) cout<<"^"<<x<<endl
#define rep(i,x,y) for(int i=x;i<y;i++)
#define nxt cout<<endl;
#define vi vector<int>
#define vp vector<pair<int,int>>
#define vvi vector<vector<int>>
#define vc vector<char>

void solve(){
int n;
in(n);
vi v(n);
rep(i,0,n){
    in(v[i]);
}
if(n==1){
    out(0);
    return;
}
int cnt=0;
vp pp;
map<pair<int,int>,int>mp;
map<pair<int,int>,int>mpp;
for(int i=0;i<n;i++){
    for(int j=i+1;j<n;j++){
        if(v[i]>v[j]){
            cnt++;
            pp.push_back({v[i],v[j]});
        }else{
            cnt+=2;
            pp.push_back({v[i],v[j]});
            pp.push_back({v[j],v[i]});
        }
    }
}
vi tmp(n+1);
for(int i=1;i<=n;i++){
    tmp[i]=i;
}
out(cnt);
set<pair<int,int>>ss;
for(int i=0;i<pp.size();i++){
    ss.insert({pp[i].first,pp[i].second});
}
for(int i=0;i<cnt;i++){ 
    for(auto &it:ss){
        int x = it.first;
        int y = it.second;
        int z2 = tmp[x]-tmp[y];
        if(z2==1){
            cout<<x<<" "<<y<<endl;
            swap(tmp[x],tmp[y]);
            auto it2 = ss.find({x,y});
            ss.erase(it2);
            break;
        }
    }
}
}

signed main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
int t=1;
// cin>>t;
while(t--){
solve();
}
}

Solution 2 (runtime: 2171 ms):
import java.io.*;
import java.util.*;

public class Main
{
    public static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    public static  BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
    public static StringTokenizer tokenizer;
    public static void read() throws IOException {
        tokenizer = new StringTokenizer(br.readLine());
    }
    public static int Int() throws IOException {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) read();
        return Integer.parseInt(tokenizer.nextToken());
    }
    public static long Long() throws IOException {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) read();
        return Long.parseLong(tokenizer.nextToken());
    }
    public static String Str() throws IOException {
        return br.readLine();
    }

    public static Character Char() throws IOException {
        return (char)br.read();
    }

    public static long[] read(int n) throws IOException {
        long[] a = new long[n];
        for (int i = 0; i < n; i++) {
            a[i] = Long() - 1;
        }
        return a;
    }

    //-----------------------------------------------

    public static long MOD = (long) 1e9 + 7;
    public static long quickPow(long pow, long num, long MOD) {
        if (pow == 0) {
            return 1;
        }
        if (pow == 1) {
            return num % MOD;
        }
        long half = quickPow(pow / 2, num, MOD);
        long twoHalf = (half * half) % MOD;
        return (twoHalf * quickPow(pow % 2, num, MOD)) % MOD;
    }

    public static void remove(TreeMap<Long, Long> map, long key) {
        map.put(key, map.get(key) - 1);
        if (map.get(key) == 0) map.remove(key);
    }

    public static void remove(HashMap<Long, Long> map, long key) {
        map.put(key, map.get(key) - 1);
        if (map.get(key) == 0) map.remove(key);
    }

    public static void add(TreeMap<Long, Long> map, long key) {
        map.put(key, map.getOrDefault(key, 0L) + 1);
    }

    public static void add(HashMap<Long, Long> map, long key) {
        map.put(key, map.getOrDefault(key, 0L) + 1);
    }




    public static void main(String[] args) throws IOException {
        int T = 1;
        while (T > 0) {
            T--;
            int n = Int();
            int[] a = new int[n];
            int[] start = new int[n];
            HashMap<Integer, Integer> pos = new HashMap<>();
            for (int i = 0; i < n; i++) {
                a[i] = Int();
                start[i] = i + 1;
                pos.put(i + 1, i);
            }
            ArrayList<int[]> res = new ArrayList<>();
            for (int i = n - 1; i >= 0; i--) {
                int position = pos.get(a[i]);
                for (int j = position; j > 0; j--) {
                    res.add(new int[] {start[j], start[j - 1]});
                    pos.put(start[j], j - 1);
                    pos.put(start[j - 1], j);
                    int tmp = start[j];
                    start[j] = start[j - 1];
                    start[j - 1] = tmp;
                }
            }
            System.out.println(res.size());
            for (int i = 0; i < res.size(); i++) {
                System.out.println(res.get(i)[0] + " " + res.get(i)[1]);
            }
        }
    }
}