Антон_Задача 2. Реверс

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;
using ui = unsigned int;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vll = vector<ll>;
using vvi = vector<vi>;
using vpii = vector<pii>;
template <typename key_type, typename value_type, typename comp = less<key_type>>
using rbt_map = tree<key_type, value_type, comp, rb_tree_tag, tree_order_statistics_node_update>;
template <typename key_type, typename comp = less<key_type>>
using rbt_set = rbt_map<key_type, null_type, comp>;
#define F(i, a, b) for(int i = (int)a; i <= (int)b; i++)
#define f(i, a, b) for(int i = (int)a; i >= (int)b; i--)
#define Fk(k, i, a, b) for(int i = (int)a; i <= (int)b; i += k)
#define fk(k, i, a, b) for(int i = (int)a; i >= (int)b; i -= k)
#define PB push_back
#define MP make_pair
#define MT make_tuple
#define trans int tm = (tl + tr)>>1, l = v<<1, r = l|1
template <typename value_type, typename relax_type = value_type, typename predictor = less<value_type>>
void relax_pred(value_type& val, const relax_type& rel) { static predictor pred; if (pred(val, rel)) val = rel; }
template <typename type>
void relax_min(type& val, const type& rel) { relax_pred<type, type, greater<type>>(val, rel); }
template <typename type>
void relax_max(type& val, const type& rel) { relax_pred<type, type, less<type>>(val, rel); }
ld const PI = acos(-1);
///#include "C:\programming\structures\IO_templates\int128_io.h"
///#include "C:\programming\structures\IO_templates\fast_io.h"
///#include "C:\programming\structures\big_integer.h"
///#include "C:\programming\structures\Math\Combinatorics.h"
///using namespace combinatorics;

int const N = 5002;
int mp[N][N];
int cnt[2];
pii mv[4] = {{-1, 0}, {1, 0}, {0, 1}, {0, -1}};

void make_move(int pl, int x, int y) {
    if (mp[x][y] != 2)
        --cnt[mp[x][y]];
    mp[x][y] = pl;
    ++cnt[pl];

    for (auto [dx, dy] : mv) {
        int ex = -1, ey = -1;
        int cx = x + dx, cy = y + dy;
        for (; mp[cx][cy] != 3; cx += dx, cy += dy) {
            if (mp[cx][cy] == pl) {
                ex = cx, ey = cy;
                break;
            }
        }
        if (ex != -1) {
            cx = x + dx, cy = y + dy;
            for (; cx != ex || cy != ey; cx += dx, cy += dy) {
                if (mp[cx][cy] != 2)
                    --cnt[mp[cx][cy]];
                mp[cx][cy] = pl;
                ++cnt[pl];
            }
        }
    }
}
//#define LOCAL
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    #ifdef LOCAL
    freopen("in", "r", stdin);
    freopen("out", "w", stdout);
    #endif
    int n, m;
    cin >> n >> m;

    F(i, 0, n + 1)
        F(j, 0, m + 1)
            mp[i][j] = (i == 0 || j == 0 || i == n + 1 || j == m + 1 ? 3 : 2);

    int x, y, turn = 0;
    cin >> x >> y;
    while (x != -1) {
        make_move(turn, x, y);
        cout << cnt[0] - cnt[1] << endl;
        cin >> x >> y;
        turn ^= 1;
    }
    return 0;
}