#include "sorting.h"
#include <bits/stdc++.h>
using namespace std;
int niz[200005];
int x[600005], y[600005];
int p[600005], q[600005];
int n, m;
int prvo[200005];
int gde[200005];
int who[200005];
int tren[200005];
int trenwho[200005];
bool check(int k){
for(int i=0; i<n; i++){
gde[niz[i]] = i;
who[i] = niz[i];
tren[niz[i]] = i;
trenwho[i] = niz[i];
}
for(int i=0; i<k; i++){
swap(who[x[i]], who[y[i]]);
swap(gde[who[x[i]]], gde[who[y[i]]]);
}
for(int i=0; i<m; i++) p[i] = q[i] = 0;
int g = 0;
for(int i=0; i<n; i++){
if(gde[i] != i){
swap(trenwho[x[g]], trenwho[y[g]]);
swap(tren[trenwho[x[g]]], tren[trenwho[y[g]]]);
int u = who[i];
p[g] = tren[i];
q[g] = tren[u];
g++;
swap(trenwho[tren[i]], trenwho[tren[u]]);
swap(tren[i], tren[u]);
swap(who[gde[i]], who[gde[u]]);
swap(gde[i], gde[u]);
}
}
return g <= k;
}
int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
n = N, m = M;
for(int i=0; i<n; i++){
niz[i] = S[i];
}
for(int i=0; i<m; i++){
x[i] = X[i];
y[i] = Y[i];
}
int l = 0, r = m, res = m;
while(l <= r){
int mid = (l+r)/2;
if(check(mid)){
res = mid;
r = mid-1;
}
else l = mid+1;
}
check(res);
for(int i=0; i<res; i++){
P[i] = p[i];
Q[i] = q[i];
}
return res;
}
