Submission

Score: 100

User: Shangbin

Problemset: fireball

Language: cpp

Time: 0.002 second

Submitted On: 2026-03-09 22:44:37

//Problem = https://grader.gchan.moe/problemset/c2_knb64_fireball/statement
#include <bits/stdc++.h>
using namespace std;
#define pii pair<int, int>

const int maxn = 105;
int n, m, ques, x, y, city_cnt = 0, dir[4][2] = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};
bool mat[maxn][maxn];

bool inMap(pii pos){
    auto [i, j] = pos;
    return i >= 1 && i <= n && j >= 1 && j <= m; 
}
void dfs(pii pos){
    auto [i, j] = pos;
    if (mat[i][j] == 0) return;
    mat[i][j] = 0;
    city_cnt--;
    for (auto [ni, nj] : dir){
        ni += i, nj += j;
        if (inMap({ni, nj})) dfs({ni, nj});
    }
}

int main(){
    cin.tie(nullptr)->sync_with_stdio(0);
    cin >> n >> m >> ques;
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++){
            cin >> mat[i][j];
            if (mat[i][j] == 1) city_cnt++;
        }
    }
    while (ques--){
        cin >> x >> y;
        dfs({x, y});
        cout << city_cnt << '\n';
    }
}