#include "seats.h"
#include <bits/stdc++.h>
using namespace std;
const int MAX = 1000005;
int st[4 * MAX][5], lzy[4 * MAX][5];
void push(int node, int l, int r) {
if (l == r) {
return;
}
for (int i = 0; i < 4; i++) {
st[node + node][i] += lzy[node][i];
st[node + node + 1][i] += lzy[node][i];
lzy[node + node][i] += lzy[node][i];
lzy[node + node + 1][i] += lzy[node][i];
lzy[node][i] = 0;
}
}
void pull(int node, int l, int r) {
bool same = true;
int who = 0;
for (int i = 0; i < 4; i++) {
if (st[node + node][i] != st[node + node + 1][i]) {
same = false;
if (st[node + node][i] > st[node + node + 1][i]) {
who = 1;
}
break;
}
}
int mid = l + r >> 1;
if (st[node + node][4] == 0) {
st[node + node][4] = mid - l + 1;
}
if (st[node + node + 1][4] == 0) {
st[node + node + 1][4] = r - mid;
}
if (!same) {
for (int i = 0; i < 5; i++) {
st[node][i] = st[node + node + who][i];
}
} else {
for (int i = 0; i < 5; i++) {
st[node][i] = st[node + node][i];
}
st[node][4] += st[node + node + 1][4];
}
}
void modify(int node, int l, int r, int ll, int rr, int i, int v) {
if (st[node][4] == 0) {
st[node][4] = r - l + 1;
}
if (l > r || l > rr || r < ll) return;
if (ll <= l && r <= rr) {
st[node][i] += v;
lzy[node][i] += v;
push(node, l, r);
return;
}
int mid = l + r >> 1;
push(node, l, r);
modify(node + node, l, mid, ll, rr, i, v);
modify(node + node + 1, mid + 1, r, ll, rr, i, v);
pull(node, l, r);
}
int solve() {
for (int i = 0; i < 4; i++) {
if (st[1][i] != 1) {
return 0;
}
}
return st[1][4];
}
vector<vector<int>> a;
int h, w;
int x[MAX];
int y[MAX];
vector<vector<int>> dx = {{-1, 0, -1}, {-1, 0, -1}, {1, 0, 1}, {1, 0, 1}};
vector<vector<int>> dy = {{0, -1, -1}, {0, 1, 1}, {0, -1, -1}, {0, 1, 1}};
void add(int p, int i, int j, int v) {
for (int dir = 0; dir < 4; dir++) {
int q = h * w;
for (int d = 0; d < 3; d++) {
int ni = i + dx[dir][d];
int nj = j + dy[dir][d];
if (ni >= 0 && ni < h && nj >= 0 && nj < w) {
q = min(q, a[ni][nj]);
}
}
--q;
if (q < p) {
continue;
}
modify(1, 0, h * w - 1, p, q, dir, v);
}
}
vector<vector<bool>> was;
void give_initial_chart(int H, int W, vector<int> R, vector<int> C) {
h = H;
w = W;
a.resize(H);
was.resize(H);
for (int i = 0; i < H; i++) {
a[i].resize(W);
was[i].resize(W);
}
for (int i = 0; i < H * W; i++) {
x[i] = R[i];
y[i] = C[i];
a[x[i]][y[i]] = i;
}
for (int i = 0; i < H * W; i++) {
add(i, x[i], y[i], 1);
}
solve();
}
vector<int> di = {0, 0, 0, -1, -1, -1, 1, 1, 1};
vector<int> dj = {0, 1, -1, 0, 1, -1, 0, 1, -1};
bool Valid(int i, int j) {
return i >= 0 && i < h && j >= 0 && j < w && !was[i][j];
}
vector<pair<int, int>> aux;
int swap_seats(int i, int j) {
for (int d = 0; d < 9; d++) {
{
int ni = x[i] + di[d];
int nj = y[i] + dj[d];
if (Valid(ni, nj)) {
add(a[ni][nj], ni, nj, -1);
was[ni][nj] = true;
aux.emplace_back(ni, nj);
}
}
{
int ni = x[j] + di[d];
int nj = y[j] + dj[d];
if (Valid(ni, nj)) {
add(a[ni][nj], ni, nj, -1);
was[ni][nj] = true;
aux.emplace_back(ni, nj);
}
}
}
for (auto& c : aux) {
was[c.first][c.second] = false;
}
aux.clear();
swap(a[x[i]][y[i]], a[x[j]][y[j]]);
swap(x[i], x[j]);
swap(y[i], y[j]);
for (int d = 0; d < 9; d++) {
{
int ni = x[i] + di[d];
int nj = y[i] + dj[d];
if (Valid(ni, nj)) {
add(a[ni][nj], ni, nj, 1);
was[ni][nj] = true;
aux.emplace_back(ni, nj);
}
}
{
int ni = x[j] + di[d];
int nj = y[j] + dj[d];
if (Valid(ni, nj)) {
add(a[ni][nj], ni, nj, 1);
was[ni][nj] = true;
aux.emplace_back(ni, nj);
}
}
}
for (auto& c : aux) {
was[c.first][c.second] = false;
}
aux.clear();
return solve();
}
/*
2 3 2
0 0
1 0
1 1
0 1
0 2
1 2
0 5
0 5
*/
