#include "seats.h"
#ifdef NYAOWO
#include "grader.cpp"
#endif
#include <bits/stdc++.h>
#define For(i, a, b) for(int i = a; i <= b; i++)
#define Forr(i, a, b) for(int i = a; i >= b; i--)
#define F first
#define S second
#define eb emplace_back
#define all(x) x.begin(), x.end()
#define sz(x) ((int)x.size())
using namespace std;
using i32 = int32_t;
using LL = long long;
using pii = pair<int, int>;
const int MAXN = 1'000'000;
const int MAXND = MAXN * 4;
const int INF = MAXN + 8;
#define L(id) ((id) * 2 + 1)
#define R(id) ((id) * 2 + 2)
struct SegTree {
struct Node {
int mn, cnt, add;
} a[MAXND];
void pull(int id) {
a[id].mn = min(a[L(id)].mn, a[R(id)].mn);
a[id].cnt = 0;
if(a[L(id)].mn == a[id].mn) a[id].cnt += a[L(id)].cnt;
if(a[R(id)].mn == a[id].mn) a[id].cnt += a[R(id)].cnt;
a[id].mn += a[id].add;
}
void build(int id, int l, int r) {
a[id].mn = 0;
a[id].cnt = r - l + 1;
a[id].add = 0;
if(l == r) return;
int m = (l + r) / 2;
build(L(id), l, m);
build(R(id), m + 1, r);
}
void add(int id, int l, int r, int L, int R, int val) {
if(l >= L && r <= R) {
a[id].mn += val;
a[id].add += val;
return;
}
int m = (l + r) / 2;
if(L <= m) add(L(id), l, m, L, R, val);
if(R > m) add(R(id), m + 1, r, L, R, val);
pull(id);
}
int query() {
// assert(a[0].mn >= 4);
if(a[0].mn != 4) return 0;
return a[0].cnt;
}
void out(int id, int l, int r, int tot) {
tot += a[id].add;
if(l == r) {
cerr << tot << " ";
return;
}
int m = (l + r) / 2;
out(L(id), l, m, tot);
out(R(id), m + 1, r, tot);
if(!id) cerr << "\n";
}
} seg;
int h, w, hw;
vector<vector<int>> g; // grid
int r[MAXN + 10];
int c[MAXN + 10];
inline void update_2x2(int i, int j, int val) {
int vals[] = {g[i][j], g[i + 1][j], g[i][j + 1], g[i + 1][j + 1]};
sort(vals, vals + 4);
seg.add(0, 0, hw - 1, vals[0], vals[1] - 1, val);
if(vals[2] != hw) seg.add(0, 0, hw - 1, vals[2], vals[3] - 1, 8 * val);
}
inline void update(int i, int j, int val) {
update_2x2(i - 1, j - 1, val);
update_2x2(i - 1, j , val);
update_2x2(i , j - 1, val);
update_2x2(i , j , val);
}
void give_initial_chart(int H, int W, std::vector<int> R, std::vector<int> C) {
h = H; w = W; hw = h * w;
seg.build(0, 0, hw - 1);
g.resize(h + 2);
For(i, 0, h + 1) g[i].resize(w + 2, hw);
For(i, 0, hw - 1) {
r[i] = R[i] + 1;
c[i] = C[i] + 1;
g[r[i]][c[i]] = i;
}
For(i, 0, h) For(j, 0, w) {
update_2x2(i, j, 1);
}
// seg.out(0, 0, hw - 1, 0);
// For(i, 0, h + 1) For(j, 0, w + 1) {
// cerr << g[i][j] << " \n"[j == w + 1];
// }
}
int swap_seats(int a, int b) {
update(r[a], c[a], -1);
update(r[b], c[b], -1);
swap(g[r[a]][c[a]], g[r[b]][c[b]]);
swap(r[a], r[b]);
swap(c[a], c[b]);
update(r[a], c[a], 1);
update(r[b], c[b], 1);
return seg.query();
}
/*
2 3 2
0 0
1 0
1 1
0 1
0 2
1 2
0 5
0 5
*/
