#include "seats.h"
#include <bits/stdc++.h>
using namespace std;
#define mp make_pair
using ii = pair<int, int>;
int H, W;
vector<int> R, C, delta;
vector<vector<int> > grid;
int cell(int r, int c, int v) {
if (!(-1 <= r && r < H && -1 <= c && c < W)) return 0;
int ret = 0;
for (int dr : {0, 1}) {
for (int dc : {0, 1}) {
int nr = r + dr, nc = c + dc;
if (0 <= nr && nr < H && 0 <= nc && nc < W && grid[nr][nc] <= v) {
ret++;
}
}
}
return ret;
}
struct node {
node *left, *right;
int S, E, sum;
ii val;
void combine() {
assert(S != E);
auto right_val = right->val;
right_val.first += left->sum;
sum = left->sum + right->sum;
if (left->val.first == right_val.first) {
val = mp(left->val.first, left->val.second + right_val.second);
} else {
val = min(left->val, right_val);
}
}
node(int _s, int _e) : S(_s), E(_e) {
if (S == E) {
sum = val.first = delta[S];
val.second = 1;
return;
}
int M = (S + E) / 2;
left = new node(S, M);
right = new node(M + 1, E);
combine();
}
void upd(int p) {
if (S == E) {
sum = val.first = delta[S];
val.second = 1;
return;
}
int M = (S + E) / 2;
if (p <= M) left->upd(p);
else right->upd(p);
combine();
}
} *root;
void upd(int x) {
delta[x] = 0;
for (int dr : {-1, 0}) {
for (int dc : {-1, 0}) {
int nr = R[x] + dr, nc = C[x] + dc, tmp = cell(nr, nc, x - 1);
if (tmp == 1 || tmp == 3) {
delta[x]--;
}
}
}
for (int dr : {-1, 0}) {
for (int dc : {-1, 0}) {
int nr = R[x] + dr, nc = C[x] + dc, tmp = cell(nr, nc, x);
if (tmp == 1 || tmp == 3) {
delta[x]++;
}
}
}
}
void give_initial_chart(int H, int W, vector<int> R, vector<int> C) {
::H = H;
::W = W;
::R = R;
::C = C;
delta.resize(H * W);
::grid = vector<vector<int> >(H, vector<int>(W, 0));
for (int i = 0; i < H * W; i++) {
grid[R[i]][C[i]] = i;
}
for (int i = 0; i < H * W; i++) {
upd(i);
}
root = new node(0, H * W - 1);
}
int swap_seats(int a, int b) {
swap(grid[R[a]][C[a]], grid[R[b]][C[b]]);
swap(R[a], R[b]);
swap(C[a], C[b]);
for (auto [r, c] : {mp(R[a], C[a]), mp(R[b], C[b])}) {
for (int dr = -1; dr <= 1; dr++) {
for (int dc = -1; dc <= 1; dc++) {
int nr = r + dr, nc = c + dc;
if (0 <= nr && nr < H && 0 <= nc && nc < W) {
upd(grid[nr][nc]);
root->upd(grid[nr][nc]);
}
}
}
}
return root->val.second;
}
