// M
#include<bits/stdc++.h>
#include "seats.h"
#define pb push_back
#define lc (id << 1)
#define rc (lc ^ 1)
#define md ((l + r) >> 1)
using namespace std;
const int MXN = 1e6 + 10, N = 1009;
int n, m, R[MXN], C[MXN], B[MXN];
int MN[MXN * 4], LZ[MXN * 4], Cnt[MXN * 4];
vector < vector < int > > A;
void Build(int id = 1, int l = 0, int r = m)
{
Cnt[id] = r - l;
if (r - l < 2)
return ;
Build(lc, l, md);
Build(rc, md, r);
}
inline void Shift(int id)
{
MN[lc] += LZ[id];
MN[rc] += LZ[id];
LZ[lc] += LZ[id];
LZ[rc] += LZ[id];
LZ[id] = 0;
}
void Add(int le, int ri, int val, int id = 1, int l = 0, int r = m)
{
if (ri <= l || r <= le)
return ;
if (le <= l && r <= ri)
{
MN[id] += val;
LZ[id] += val;
return ;
}
Shift(id);
Add(le, ri, val, lc, l, md);
Add(le, ri, val, rc, md, r);
MN[id] = min(MN[lc], MN[rc]);
Cnt[id] = 0;
if (MN[id] == MN[lc]) Cnt[id] += Cnt[lc];
if (MN[id] == MN[rc]) Cnt[id] += Cnt[rc];
}
inline void Do(int i, int val)
{
//printf("%d : %d ::: %d\n", min(B[i], B[i + 1]), max(B[i], B[i + 1]), val);
Add(min(B[i], B[i + 1]), max(B[i], B[i + 1]), val);
}
void give_initial_chart(int _H, int _W, vector < int > _R, vector < int > _C)
{
n = _H; m = _W;
for (int i = 0; i < n * m; i ++)
R[i] = _R[i], C[i] = _C[i];
for (int i = 0; i < n; i ++)
A.pb(vector < int > (m, 0));
for (int i = 0; i < n * m; i ++)
A[R[i]][C[i]] = i;
assert(n == 1);
for (int i = 0; i < m; i ++)
B[C[i] + 1] = i;
Build();
B[0] = B[m + 1] = m + 1;
for (int i = 0; i <= m; i ++)
Do(i, 1);
}
int swap_seats(int a, int b)
{
swap(R[a], R[b]);
swap(C[a], C[b]);
int c = C[a] + 1;
int d = C[b] + 1;
if (c > d)
swap(c, d);
Do(c - 1, -1);
Do(c, -1);
if (d - 1 > c)
Do(d - 1, -1);
Do(d, -1);
swap(B[c], B[d]);
Do(c - 1, 1);
Do(c, 1);
if (d - 1 > c)
Do(d - 1, 1);
Do(d, 1);
return Cnt[1];
}
