#include "sorting.h"
#include "bits/stdc++.h"
using namespace std;
int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
if (is_sorted(S, S + N)) {
return 0;
}
auto check = [&](int mid) {
vector<int> finalArray(N);
for (int i = 0; i < N; ++i) {
finalArray[i] = S[i];
}
for (int i = 0; i < mid; ++i) {
swap(finalArray[X[i]], finalArray[Y[i]]);
}
vector<int> next(N);
vector<pair<int, int>> swaps;
for (int i = 0; i < N; ++i) {
next[i] = finalArray[i];
}
vector<bool> vis(N);
for (int i = 0; i < N; ++i) {
if (vis[i] || next[i] == i) continue;
int cur = i, nxt = next[i];
vis[i] = true;
while (nxt != i) {
vis[nxt] = true;
swaps.emplace_back(cur, nxt);
cur = nxt;
nxt = next[cur];
}
}
vector<int> idx(N);
vector<int> currentArray(N);
for (int i = 0; i < N; ++i) {
idx[S[i]] = i;
currentArray[i] = S[i];
}
auto swapp = [&](int x, int y) {
swap(idx[x], idx[y]);
swap(currentArray[idx[x]], currentArray[idx[y]]);
};
for (int i = 0; i < (int) swaps.size(); ++i) {
int x = currentArray[X[i]], y = currentArray[Y[i]];
swapp(x, y);
auto [p, q] = swaps[i];
P[i] = idx[p], Q[i] = idx[q];
swapp(p, q);
}
for (int i = (int) swaps.size(); i < mid; ++i) {
P[i] = Q[i] = 0;
}
return (int) swaps.size() <= mid;
};
int l = 0, r = M;
while (l < r) {
int mid = (l + r) / 2;
if (check(mid)) {
r = mid;
} else {
l = mid + 1;
}
}
check(l);
return l;
}
