#include "sorting.h"
#include <bits/stdc++.h>
using namespace std;
const int mxN = (int)2e5+10;
int n, a[mxN], temp[mxN], x[mxN], y[mxN], pos[mxN];
void swp(int i, int j){
if(i==j) return;
swap(pos[a[i]],pos[a[j]]), swap(a[i],a[j]);
}
int chk(int m, int P[], int Q[]){
for(int i = 0; i < n; i++)
a[i] = temp[i], pos[a[i]] = i;
for(int i = 0; i < m; i++)
swp(x[i],y[i]), P[i]=Q[i]=0;
int tot = 0;
for(int i = 0; i < n; i++){
if(pos[i]==i) continue;
P[tot] = i, Q[tot] = pos[i];
swp(P[tot],Q[tot]), tot++;
}
if(is_sorted(a,a+n) and tot<=m) return m;
return mxN;
}
int findSwapPairs(int N, int A[], int m, int X[], int Y[], int P[], int Q[]) {
n = N;
for(int i = 0; i < n; i++)
a[i] = temp[i] = A[i];
for(int i = 0; i < m; i++)
x[i] = X[i], y[i] = Y[i], P[i]=Q[i]=0;
int l = 0, r = m;
while(l<r){
int mid = (l+r)/2;
if(chk(mid,P,Q)<=mid) r=mid;
else l=mid+1;
}
return chk(l,P,Q);
}
