uva 352 - The Seasonal War

 1 #include <cstdio>
 2 using namespace std;
 3 
 4 char image[30][30];
 5 
 6 void DFS(int &n, int i, int j)
 7 {
 8     image[i][j] = ‘0‘;
 9     if (i-1 >= 0 && image[i-1][j] == ‘1‘) DFS(n, i-1, j);
10     if (i+1 <  n && image[i+1][j] == ‘1‘) DFS(n, i+1, j);
11     if (j-1 >= 0 && image[i][j-1] == ‘1‘) DFS(n, i, j-1);
12     if (j+1 <  n && image[i][j+1] == ‘1‘) DFS(n, i, j+1);
13     if (i-1 >= 0 && j-1 >= 0 && image[i-1][j-1] == ‘1‘) DFS(n, i-1, j-1);
14     if (i-1 >= 0 && j+1 <  n && image[i-1][j+1] == ‘1‘) DFS(n, i-1, j+1);
15     if (i+1 <  n && j-1 >= 0 && image[i+1][j-1] == ‘1‘) DFS(n, i+1, j-1);
16     if (i+1 <  n && j+1 <  n && image[i+1][j+1] == ‘1‘) DFS(n, i+1, j+1);
17 }
18 
19 int main()
20 {
21     // freopen ("input.txt","rt",stdin);
22     int n,Case = 1;
23     while (scanf("%d", &n) != EOF){
24         getchar();
25         for (int i = 0; i < n; ++i)
26             gets(image[i]);
27         int num = 0;
28         for (int i = 0; i < n; ++i)
29             for (int j = 0; j < n; ++j)
30                 if (image[i][j] == ‘1‘){
31                     DFS(n, i, j);
32                     ++num;
33                 }
34         printf("Image number %d contains %d war eagles.\n", Case++, num);
35     }
36     return 0;
37 }