Description
There is a rectangular room, covered with square tiles. Each tile is colored either red or black. A man is standing on a black tile. From a tile, he can move to one of four adjacent tiles. But he can't move on red tiles, he can
move only on black tiles.
Write a program to count the number of black tiles which he can reach by repeating the moves described above.
move only on black tiles.
Write a program to count the number of black tiles which he can reach by repeating the moves described above.
Input
The input consists of multiple data sets. A data set starts with a line containing two positive integers W and H; W and H are the numbers of tiles in the x- and y- directions, respectively. W and H are not more than 20.
There are H more lines in the data set, each of which includes W characters. Each character represents the color of a tile as follows.
'.' - a black tile
'#' - a red tile
'@' - a man on a black tile(appears exactly once in a data set)
The end of the input is indicated by a line consisting of two zeros.
There are H more lines in the data set, each of which includes W characters. Each character represents the color of a tile as follows.
'.' - a black tile
'#' - a red tile
'@' - a man on a black tile(appears exactly once in a data set)
The end of the input is indicated by a line consisting of two zeros.
Output
For each data set, your program should output a line which contains the number of tiles he can reach from the initial tile (including itself).
Sample Input
6 9
....#.
.....#
......
......
......
......
......
#@...#
.#..#.
11 9
.#.........
.#.#######.
.#.#.....#.
.#.#.###.#.
.#.#..@#.#.
.#.#####.#.
.#.......#.
.#########.
...........
11 6
..#..#..#..
..#..#..#..
..#..#..###
..#..#..#@.
..#..#..#..
..#..#..#..
7 7
..#.#..
..#.#..
###.###
...@...
###.###
..#.#..
..#.#..
0 0
Sample Output
45
59
6
13 思路:使用递归,对@所在的位置四个方向查找,一直到不满足条件h>=n||l>=m||h<0||l<0||str[h][l]=='#'||boo[h][l]==1为止。。。 #include <iostream>
#include <string>
#include<algorithm> //头文件
using namespace std;
bool boo[25][25];
string str[21];
int jishu=0;
int m,n,h=0,l=0;//h为行,l为列
void search(int h,int l)
{
if(h>=n||l>=m||h<0||l<0||str[h][l]=='#'||boo[h][l]==1) //此处如果没有||boo[h][l]==1就会死循环,但是却不显示一直进行,而是程序莫名其妙的结束,以后注意!!!!!!!!!!!!!!
return ;
boo[h][l]=1;
jishu++; search(h,l-1);
search(h,l+1);
search(h-1,l);
search(h+1,l);
}
int main()
{
int i,j;
cin>>m>>n;//m是一个字符串的长度 n是字符串数目
while(m!=0&&n!=0)
{ jishu=0;
h=0,l=0;
for(i=0;i<n;i++)
{
cin>>str[i];
for(j=0;j<m;j++)
if(str[i][j]=='@')
{
h=i;
l=j;
}
}
memset(boo,0,25*25);
search(h,l);
cout<<jishu<<endl;
cin>>m>>n;
}
return 0;
}