思路:
flood fill算法
#include <iostream>
using namespace std;
#include <algorithm>
#include <cstring>
#include <string>
const static int N = 110;
int t, n, m;
string g[N];
bool st[N][N];
void M(int x, int y, int z)
{
g[x][y] = z + '0';
}
void dfs(int x, int y)
{
st[x][y] = true;
int dx[] = {-1, 0, 1, 0}, dy[] = {0, 1, 0, -1};
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) continue;
if(st[a][b]) continue;
if(g[a][b] == '0') continue;
dfs(a, b);
}
}
int Q()
{
int cnt = 0;
for(int i = 0; i < n; ++i)
for(int j = 0; j < m; ++j)
{
if(!st[i][j] && g[i][j] == '1')
{
dfs(i, j);
++cnt;
}
}
return cnt;
}
int main()
{
cin >> t;
int p = t;
while(t --)
{
cout << "Case #" << p - t << ":" << endl;
cin >> n >> m;
for(int i = 0; i < n; ++i) cin >> g[i];
int k;
cin >> k;
char opt;
int x, y, z;
while(k--)
{
cin >> opt;
if(opt == 'M')
{
cin >> x >> y >> z;
M(x, y, z);
}
else
{
memset(st, 0, sizeof st);
cout << Q() << endl;
}
}
}
}