cars1600.cpp

// #include<bits/stdc++.h>
#include<iostream>
#include<vector>
#include<algorithm>
#include<map>
#include<set>
#include<string>
using namespace std;

typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<string> vs;
typedef vector<long long> vll;
typedef vector<vector<ll> > vvll;

#define fastio() ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define pb push_back
#define mp make_pair
#define sz(x) ((int)(x).size())
#define all(x) x.begin(),x.end()

ll max(ll a, ll b, ll c){ return max(a, max(b, c));}
ll min(ll a, ll b, ll c){ return min(a, min(b, c));}
ll gcd(ll a, ll b) {if (b > a) {return gcd(b, a);} if (b == 0) {return a;} return gcd(b, a % b);}
ll fact(ll a) { return (a <= 1) ? 1 : a * fact(a - 1); }

vll factors(int n) { vll ans; int l = sqrt(n); for (int i = 1; i <= l; i++) { if (n % i == 0){ if (n/i == i) ans.pb(i); else {ans.pb(i); ans.pb(n/i);}}} return ans;}
string DecimalToBinary(ll num){string str; while(num){if(num & 1) str.pb('1');else str.pb('0');num>>=1;}return str;}
ll BinaryToDecimal(string num){ll ans = 0; ll base = 1; for (int i = sz(num) - 1; i >= 0; i--) {if (num[i] == '1') ans += base; base<<=1;}return ans;}


int findpos(int val,vi &temp){
    for(int i = 0; i < sz(temp); i++){
        if(temp[i] == val) return i;
    }
    return -1;
}

void generatemoves(vi &intial,vi &final,vector<pii> &moves){

    for(int i = 0; i < sz(intial); i++){
        if(intial[i] == final[i]) continue;
        else{
            int pos = findpos(final[i],intial);
            for(int j = pos; j > i; j--){
                moves.pb(mp(intial[j],intial[j - 1]));
                swap(intial[j],intial[j - 1]);
            }
        }
    }
    return;
} 


void Vedant(){
    int n;
    cin >> n;
    vi final(n);
    for(int i = 0; i < n; i++) cin >> final[i];

    vi temp = final;
    reverse(all(temp));

    vector<pii> moves;
    vi intital;
    for(int i = 1; i <= n; i++) intital.pb(i);

    generatemoves(intital,temp,moves);
    generatemoves(temp,final,moves);

    cout << moves.size() << endl;
    for(auto it : moves){
        cout << it.first << " " << it.second << endl;
    }
    return;
}


int main(){
    fastio();
    int t = 1;
    while(t--){
       Vedant();
    }
    return 0;
}