90pts,WA on #3

#include <iostream>
using namespace std;
const int MAXN = 1005, MAXM = 100005;
int n, m, pos, p, q, tmp_ans;
bool map[MAXN][MAXN];
int tag[MAXN][MAXN], ans[MAXM];
void dfs(int x, int y, int f = -1){
    if(x < 1 || y < 1 || x > n || y > n) return;
    if(tag[x][y] != 0) return;
    if(f != -1 && map[x][y] != f) return;
    tag[x][y] = pos;
    tmp_ans++;
    for(int i = -1; i <= 1; i++){
        dfs(x + i, y, map[x][y]);
		dfs(x, y + i, map[x][y]);
	}
    return;
}
int main(){
    cin >> n >> m;
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= n; j++){
            char ch;
            cin >> ch;
            map[i][j] = (ch == '1') ^ (i % 2) ^ (j % 2);
        }
    }
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= n; j++){
            if(tag[i][j] == 0){
                pos++;
                tmp_ans = 0;
				dfs(i, j);
                ans[pos] = tmp_ans;
            }
        }
    }
    for(int i = 1; i <= m; i++){
        cin >> p >> q;
        cout << ans[tag[p][q]] << endl;
    }
    return 0;
}