洛谷 P1506. 拯救oibh总部
原题链接
中等
作者:
我是java同学
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2024-01-14 19:52:32
,
所有人可见
,
阅读 40
#include <bits/stdc++.h>
using namespace std;
const int N = 510;
int n, m;
char g[N][N];
int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};
void dfs(int x, int y) {
g[x][y] = '*';
for (int i = 0; i < 4; i ++ ) {
int a = x + dx[i], b = y + dy[i];
if (a >= 0 && a < n && b >= 0 && b < m && g[a][b] == '0')
dfs(a, b);
}
}
int main() {
cin >> n >> m;
for (int i = 0; i < n; i ++ ) cin >> g[i];
for (int i = 0; i < n; i ++ )
for (int j = 0; j < m; j ++ )
if (g[i][j] == '0') {
if (i == 0 || i == n - 1) dfs(i, j);
if (j == 0 || j == m - 1) dfs(i, j);
}
int res = 0;
for (int i = 0; i < n; i ++ ) {
for (int j = 0; j < m; j ++ )
if (g[i][j] == '0')
res ++ ;
}
printf("%d\n", res);
return 0;
}