> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
> 
> /* ---- stack data-structure ---- */
> struct pos {
> 	int row;
> 	int col;
> 	struct pos *next;
> };
> 
> struct pos *head, *tail;
> 
> /* ---- operatioin of stack ---- */
> void
> init(void)
> {
> 	head = tail = NULL;
> }
> 
> void
> push(int row, int col)
> {
> 	struct pos *tmp = NULL;
> 
> 	if (head == NULL && tail == NULL) {
> 		tmp = (struct pos*)malloc(sizeof(struct pos));
> 		if (tmp == NULL)
> 			exit(-1);
> 		tmp->row = row;
> 		tmp->col = col;
> 		head = tail = tmp;
> 	} else {
> 		tmp = (struct pos*)malloc(sizeof(struct pos));
> 		if (tmp == NULL)
> 			exit(-1);
> 		tmp->row = row;
> 		tmp->col = col;
> 		tmp->next = head;
> 		head = tmp;
> 	}
> }
> 
> int
> pop(int *row, int *col)
> {
> 	struct pos *tmp = NULL;
> 
> 	if (head == tail) {
> 		if (head == NULL)
> 			return 1;
> 		*row = head->row;
> 		*col = head->col;
> 		free(head);
> 		head = tail = NULL;
> 	} else {
> 		*row = head->row;
> 		*col = head->col;
> 		tmp = head;
> 		head = tmp->next;
> 		free(tmp);
> 	}
> 	return 0;
> }
> 
> /* ---- main algorithm for dealing the problem ---- */
> void
> castle(int (*room)[70], int row, int col)
> {
> 	int flag[50][50] = {};	// array of flags for deciding which cell is accessed, which one is not
> 	int i, j, cur_row, cur_col, cell;
> 	int cnt, cnt_cell, ret, max;
> 	// this two variable is just for debugging ---- int m, n;
> 	
> 	init();					// initialize the stack data-structure
> 	cnt = 0;				// number of rooms
> 	cnt_cell = 0;			// count of cells of one room
> 	max = 0;				// the number of cells which the largest room has
> 	cur_row = cur_col = 0;
> 	cell = 0;
> 	ret = 0;
> 
> 	for (i = 0;i < row;i++)
> 		for (j = 0;j < col;j++) {
> 			if (flag[i][j] == 0) {
> 				push(i,j);
> 				cnt_cell++;
> 				flag[i][j] = 1;
> 				cur_row = i;
> 				cur_col = j;
> 				while (1) {
> 					cell = room[cur_row][cur_col];
> 					if (!(cell&1)) {
> 						push(cur_row,cur_col-1);
> 						if (flag[cur_row][cur_col-1] == 0)
> 							cnt_cell++;
> 						flag[cur_row][cur_col-1] = 1;
> 						room[cur_row][cur_col] |= 1;
> 						cur_col = cur_col - 1;
> 						room[cur_row][cur_col] |= 4;
> 					} else if (!(cell&2)) {
> 						push(cur_row-1,cur_col);
> 						if (flag[cur_row-1][cur_col] == 0)
> 							cnt_cell++;
> 						flag[cur_row-1][cur_col] = 1;
> 						room[cur_row][cur_col] |= 2;
> 						cur_row = cur_row - 1;
> 						room[cur_row][cur_col] |= 8;
> 					} else if (!(cell&4)) {
> 						push(cur_row,cur_col+1);
> 						if (flag[cur_row][cur_col+1] == 0)
> 							cnt_cell++;
> 						flag[cur_row][cur_col+1] = 1;
> 						room[cur_row][cur_col] |= 4;
> 						cur_col = cur_col + 1;
> 						room[cur_row][cur_col] |= 1;
> 					} else if (!(cell&8)) {
> 						push(cur_row+1,cur_col);
> 						if (flag[cur_row+1][cur_col] == 0)
> 							cnt_cell++;
> 						flag[cur_row+1][cur_col] = 1;
> 						room[cur_row][cur_col] |= 8;
> 						cur_row = cur_row + 1;
> 						room[cur_row][cur_col] |= 2;
> 					} else {
> 						ret = pop(&cur_row,&cur_col);
> 						if (ret != 0)
> 							break;
> 					}
> 				} //end of while
> 				if (cnt_cell > max)
> 					max = cnt_cell;
> 				cnt_cell = 0;
> 				cnt++;
> 				/* this is for debugging, to print the status of every cell
> 				for (m = 0;m < row;m++) {
> 					for (n = 0;n < col;n++)
> 						printf("%d ",flag[m][n]);
> 					printf("\n");
> 				}
> 				
> 				printf("\n");
> 				*/
> 			} // end of if
> 		} // end of second for
> 
> 	printf("%d\n",cnt);
> 	printf("%d\n",max);
> 
> 	return;
> }
> 
> 
> int
> main(void)
> {
> 	int row, col, i, j, val;
> 	int room[70][70] = {};
> 	
> 	scanf("%d",&row);
> 	scanf("%d",&col);
> 
> 	if (row < 0 || row > 50 || col < 0 || col > 50)
> 		exit(-1);
> 
> 	for (i = 0;i < row;i++) {
> 		for (j = 0;j < col;j++) {
> 			scanf("%d",&val);
> 			if (val < 0 || val > 15)
> 				exit(-1);
> 			room[i][j] = val;
> 		}
> 	}
> 
> 	castle(room,row,col);
> 
> /* just for print the array
> 	for (i = 0;i < row;i++) {
> 		for (j = 0;j < col; j++)
> 			printf("%d ",room[i][j]);
> 		printf("\n");
> 	}
> */
> 	return 0;
> }

终于解决了，一定要注意正确处理四周都无墙的情况， 及数值为 0。

我就是没有处理好这个情况猜一直WA的。