UVa 572 Oil Deposits

Description

经典floodfill
…

Hint

记得判断边界

Code

#include <cstdio>
#include <cstring>
#include <iostream>
#include <stack>
using namespace std;
int m, n;
const int maxm = 100 + 9;
const int maxn = 100 + 9;
const int dx[8] = {0, 0, 1, 1, 1, -1, -1, -1};
const int dy[8] = {1, -1,0, 1, -1, 0, 1, -1 };
bool g[maxm][maxn];
struct V
{
  int x, y;
  V(int x, int y) : x(x), y(y) {}
};
void print()
{
  for (int i = 0; i < m; i++)
  {
    for (int j = 0; j < n; j++)
      if (g[i][j]) cout << '@'; else cout << '*';
    cout << endl;
  }
  cout << endl;
}
void solve()
{
  memset(g, 0, sizeof(g));
  for (int i = 0; i < m; i++)
  {
    for (int j = 0; j < n; j++)
    {
      char ch;
      cin >> ch;
      if (ch == '@') g[i][j] = true;
    }
    scanf("\n");
  }
  int ans = 0;
  for (int i = 0; i < m; i++)
    for (int j = 0; j < n; j++)
      if (g[i][j])
      {
        stack<V> s;
        s.push(V(i, j));
        while (!s.empty())
        {
          V now = s.top();
          s.pop();
          g[now.x][now.y] = false;
          for (int k = 0; k < 8; k++)
          {
            int x = now.x + dx[k];
            int y = now.y + dy[k];
            if (x < 0 || x >= m || y < 0 || y >= n) continue;
            if (g[x][y]) s.push(V(x, y));
          }
        }
        ans++;
      }
  cout << ans << endl;
}
int main()
{
// freopen("input.txt", "r", stdin);
  for (;;)
  {
    cin >> m >> n;
    if (m == 0) break;
    solve();
  }
}