Codeforces 489A SwapSort

//#pragma comment(linker, "/STACK:16777216") //for c++ Compiler
#include <stdio.h>
#include <iostream>
#include <cstring>
#include <cmath>
#include <stack>
#include <queue>
#include <vector>
#include <algorithm>
#define ll long long
#define Max(a,b) (((a) > (b)) ? (a) : (b))
#define Min(a,b) (((a) < (b)) ? (a) : (b))
#define Abs(x) (((x) > 0) ? (x) : (-(x)))
using namespace std;

const int INF = 0x3f3f3f3f;
int a[3111], b[3111], n, counti;
int ans[3111][2];

int main(){
    int i, j, t, m;
    while(EOF != scanf("%d",&n)){
        counti = 0;
        for(i = 1; i <= n; ++i){
            scanf("%d",&a[i]);
            b[i] = a[i];
        }
        sort(b + 1, b + 1 + n);
        for(i = 1; i <= n; ++i){
            if(a[i] != b[i]){
                for(j = i + 1; j <= n; ++j){
                    if(a[j] == b[i] && a[j] != b[j]){
                        swap(a[j], a[i]);
                        ++counti;
                        ans[counti][0] = j;
                        ans[counti][1] = i;
                        break;
                    }
                }
            }
        }

        printf("%d\n",counti);
        for(i = 1; i <= counti; ++i){
            printf("%d %d\n",ans[i][1] - 1, ans[i][0] - 1);
        }
    }

    return 0;
}