【HDOJ】1241 Oil Deposits

经典的BFS。

 #include <stdio.h>
 #include <string.h>

 #define MAXNUM 105
 #define MAXROW 105
 #define MAXQUE 10005

 char buf[MAXROW][MAXNUM];
 char visit[MAXROW][MAXNUM];

 typedef struct {
     int x, y;
 } pos_st;

 pos_st queue[MAXQUE];
 int direct[][] = {{,-},{-,-},{-,},{-,},{,},{,},{,},{,-}};
 int m, n;
 int total;

 void bfs();
 void search();

 int main() {
     int i;

     while (scanf("%d%d", &m, &n)!=EOF && (m||n)) {
         getchar();
         for (i=; i<m; ++i) {
             gets(buf[i]);
         }
         bfs();
         printf("%d\n", total);
     }

     return ;
 }

 void bfs() {
     int i, j;

     total = ;
     memset(visit, -, sizeof(visit));

     for (i=; i<m; ++i)
         for (j=; j<n; ++j)
             if (buf[i][j]=='@' && visit[i][j]==-)
                 search(i, j);
 }

 void search(int row, int col) {
     int front, rear;
     int x, y, newx, newy;
     int i;

     front = rear = ;
     total++;
     visit[row][col] = total;

     if (visit[row][col] > ) {
         queue[rear].x = row;
         queue[rear].y = col;
         rear++;
         while (front != rear) {
             x = queue[front].x;
             y = queue[front].y;
             front++;
             for (i=; i<; ++i) {
                 newx = x+direct[i][];
                 newy = y+direct[i][];
                 if (newx>= && newx<m && newy>= && newy<n) {
                     if (buf[newx][newy] == '@' && visit[newx][newy]<) {
                         queue[rear].x = newx;
                         queue[rear].y = newy;
                         rear++;
                         visit[newx][newy] = total;
                     }
                 }
             }
         }
     }

 }