// 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;
int n, m, k, R[MXN], C[MXN], PS[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 = k)
{
if (r - l < 2)
{
Cnt[id] = 1;
MN[id] = PS[l];
return ;
}
Build(lc, l, md);
Build(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 Shift(int id)
{
MN[lc] += LZ[id];
MN[rc] += LZ[id];
LZ[lc] += LZ[id];
LZ[rc] += LZ[id];
LZ[id] = 0;
}
int le, ri, val;
void Add(int id = 1, int l = 0, int r = k)
{
if (ri <= l || r <= le)
return ;
if (le <= l && r <= ri)
{
MN[id] += val;
LZ[id] += val;
return ;
}
Shift(id);
Add(lc, l, md);
Add(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 j, int _val)
{
vector < int > tmp = {A[i][j], A[i + 1][j], A[i][j + 1], A[i + 1][j + 1]};
sort(tmp.begin(), tmp.end());
le = tmp[0]; ri = tmp[1]; val = _val;
Add();
le = tmp[2]; ri = tmp[3]; val = _val;
Add();
}
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];
k = n * m;
for (int i = 0; i <= n + 1; i ++)
A.pb(vector < int > (m + 2, k));
for (int i = 0; i < k; i ++)
R[i] ++, C[i] ++;
for (int i = 0; i < k; i ++)
A[R[i]][C[i]] = i;
for (int i = 0; i <= n; i ++)
for (int j = 0; j <= m; j ++)
{
vector < int > tmp = {A[i][j], A[i + 1][j], A[i][j + 1], A[i + 1][j + 1]};
sort(tmp.begin(), tmp.end());
PS[tmp[0]] ++; PS[tmp[1]] --;
PS[tmp[2]] ++; PS[tmp[3]] --;
}
for (int i = 1; i < k; i ++)
PS[i] += PS[i - 1];
Build();
}
int swap_seats(int a, int b)
{
vector < pair < int , int > > vec;
for (int dx = -1; dx <= 0; dx ++)
for (int dy = -1; dy <= 0; dy ++)
vec.push_back({R[a] + dx, C[a] + dy}), vec.push_back({R[b] + dx, C[b] + dy});
sort(vec.begin(), vec.end());
vec.resize(unique(vec.begin(), vec.end()) - vec.begin());
for (auto X : vec)
Do(X.first, X.second, -1);
swap(R[a], R[b]);
swap(C[a], C[b]);
swap(A[R[a]][C[a]], A[R[b]][C[b]]);
for (auto X : vec)
Do(X.first, X.second, 1);
assert(MN[1] == 4);
return Cnt[1];
}
