#include "seats.h"
#include <bits/stdc++.h>
using namespace std;
template<typename T>
using min_heap = priority_queue<T, vector<T>, greater<T>>;
template<typename T>
using max_heap = priority_queue<T, vector<T>, less<T>>;
using int64 = long long;
using ld = long double;
constexpr int kInf = 1e9 + 10;
constexpr int64 kInf64 = 1e15 + 10;
constexpr int kMod = 1e9 + 7;
template<class node, class F = std::function<node(const node &, const node &)>>
class SegTree {
int n = 0;
std::vector<node> t;
F unite;
void build(const int x, const int l, const int r, const std::vector<node> &a) {
if (l == r) {
t[x] = a[l];
return;
}
const int mid = (l + r) / 2;
const int y = 2 * (mid - l + 1) + x;
build(x + 1, l, mid, a);
build(y, mid + 1, r, a);
t[x] = unite(t[x + 1], t[y]);
}
void update(const int x, const int l, const int r, const int p, const node &v) {
if (l == p and p == r) {
t[x] = v;
return;
}
const int mid = (l + r) / 2;
const int y = 2 * (mid - l + 1) + x;
if (p <= mid) {
update(x + 1, l, mid, p, v);
} else {
update(y, mid + 1, r, p, v);
}
t[x] = unite(t[x + 1], t[y]);
}
node query(const int x, const int l, const int r, const int ql, const int qr) const {
if (ql <= l and r <= qr) {
return t[x];
}
const int mid = (l + r) / 2;
const int y = 2 * (mid - l + 1) + x;
if (qr <= mid) {
return query(x + 1, l, mid, ql, qr);
} else if (mid < ql) {
return query(y, mid + 1, r, ql, qr);
} else {
return unite(query(x + 1, l, mid, ql, qr), query(y, mid + 1, r, ql, qr));
}
}
void debug_node(const int x, const vector<int> &path) const {
for (int i = 0; i < path.size(); i++) {
cerr << path[i] << (i == path.size() - 1 ? ": " : " -> ");
}
cerr << t[x] << '\n';
}
void debug(const int x, const int l, const int r, vector<int> path) const {
path.push_back(x);
if (l == r) {
debug_node(x, path);
return;
}
const int mid = (l + r) / 2;
const int y = 2 * (mid - l + 1) + x;
debug(x + 1, l, mid, path);
debug(y, mid + 1, r, path);
debug_node(x, path);
}
public:
SegTree() = default;
explicit SegTree(const int n, const node e, F f) : n(n), t(2 * n - 1, e), unite(std::move(f)) {}
explicit SegTree(const std::vector<node> &a, F f) : n(a.size()), t(2 * (a.size()) - 1), unite(std::move(f)) {
build(0, 0, n - 1, a);
}
void set(const int p, const node &v) {
assert(0 <= p and p < n);
update(0, 0, n - 1, p, v);
}
[[nodiscard]] node get(const int l, const int r) const {
assert(0 <= l and l <= r and r < n);
return query(0, 0, n - 1, l, r);
}
void debug() const {
debug(0, 0, n - 1, {});
cerr << "----------\n\n";
}
};
struct node {
int sum = 0;
int mini = 0;
int cnt = 0;
};
int n, m, total_seats;
vector<int> R, C;
SegTree<node> st;
vector<vector<int>> grid;
const vector<pair<int, int>> top_left = {
{-1, -1},
{-1, 0},
{0, -1},
{0, 0}};
const vector<pair<int, int>> nbr = {
{0, 0},
{0, 1},
{1, 0},
{1, 1}};
inline bool exists(const int row, const int col) {
return (0 <= row and row < n and 0 <= col and col < m);
}
inline int calc_delta(const int x) {
const int row = R[x], col = C[x];
int delta = 0;
vector<int> v;
for (auto [r, c] : top_left) {
r += R[x], c += C[x];
for (const auto &[dr, dc] : nbr) {
if (not exists(r + dr, c + dc)) continue;
v.push_back(grid[r + dr][c + dc]);
}
sort(v.begin(), v.end());
const int pos = (int)distance(v.begin(), find(v.begin(), v.end(), grid[row][col]));
if (pos == 0) delta++;
if (pos == 1) delta--;
if (pos == 2) delta++;
if (pos == 3) delta--;
v.clear();
}
return delta;
}
void give_initial_chart(const int H, const int W, std::vector<int> R_, std::vector<int> C_) {
n = H, m = W;
total_seats = n * m;
R = move(R_), C = move(C_);
grid.resize(n, vector<int>(m));
st = SegTree<node>(total_seats, node(), [&](const node &l, const node &r) {
node ret{};
ret.sum = l.sum + r.sum;
if (l.mini == l.sum + r.mini) {
ret.mini = l.mini;
ret.cnt = l.cnt + r.cnt;
} else if (l.mini < l.sum + r.mini) {
ret.mini = l.mini;
ret.cnt = l.cnt;
} else {
ret.mini = l.sum + r.mini;
ret.cnt = r.cnt;
}
return ret;
});
for (int seat = 0; seat < total_seats; seat++) {
grid[R[seat]][C[seat]] = seat;
}
for (int seat = 0; seat < total_seats; seat++) {
const int delta = calc_delta(seat);
st.set(seat, {delta, delta, 1});
}
}
int swap_seats(const int x, const int y) {
swap(grid[R[x]][C[x]], grid[R[y]][C[y]]);
swap(R[x], R[y]);
swap(C[x], C[y]);
for (const int pt : {x, y}) {
for (auto [r, c] : top_left) {
r += R[pt], c += C[pt];
for (const auto &[dr, dc] : nbr) {
if (not exists(r + dr, c + dc)) continue;
const int seat = grid[r + dr][c + dc];
const int delta = calc_delta(seat);
st.set(seat, {delta, delta, 1});
}
}
}
return st.get(0, total_seats - 1).cnt;
}
