The die is cast (DFS 双重)

针对在线游戏中的骰子投掷,开发了一款能够通过摄像头捕捉并自动识别骰子点数的程序。该程序使用双DFS算法来区分不同的骰子及其上的点数。

  The die is cast 

InterGames is a high-tech startup company that specializes in developing technology that allows users to play games over the Internet. A market analysis has alerted them to the fact that games of chance are pretty popular among their potential customers. Be it Monopoly, ludo or backgammon, most of these games involve throwing dice at some stage of the game.

Of course, it would be unreasonable if players were allowed to throw their dice and then enter the result into the computer, since cheating would be way to easy. So, instead, InterGames has decided to supply their users with a camera that takes a picture of the thrown dice, analyzes the picture and then transmits the outcome of the throw automatically.

For this they desperately need a program that, given an image containing several dice, determines the numbers of dots on the dice.

We make the following assumptions about the input images. The images contain only three dif- ferent pixel values: for the background, the dice and the dots on the dice. We consider two pixels connected if they share an edge - meeting at a corner is not enough. In the figure, pixels A and B are connected, but B and C are not.

A set S of pixels is connected if for every pair (a,b) of pixels in S, there is a sequence $a_1, a_2, \dots, a_k$ in S such that a = a1 and b = ak , and ai and ai+1 are connected for $1 \le i < k$.

We consider all maximally connected sets consisting solely of non-background pixels to be dice. `Maximally connected' means that you cannot add any other non-background pixels to the set without making it dis-connected. Likewise we consider every maximal connected set of dot pixels to form a dot.

Input 

The input consists of pictures of several dice throws. Each picture description starts with a line containing two numbers w and h, the width and height of the picture, respectively. These values satisfy  $5 \leŸw,h \le 50$ .

The following h lines contain w characters each. The characters can be: ``.'' for a background pixel, ``*'' for a pixel of a die, and ``X'' for a pixel of a die's dot.

Dice may have different sizes and not be entirely square due to optical distortion. The picture will contain at least one die, and the numbers of dots per die is between 1 and 6, inclusive.

The input is terminated by a picture starting with w = h = 0, which should not be processed.

Output 

For each throw of dice, first output its number. Then output the number of dots on the dice in the picture, sorted in increasing order.

Print a blank line after each test case.

Sample Input 

30 15
..............................
..............................
...............*..............
...*****......****............
...*X***.....**X***...........
...*****....***X**............
...***X*.....****.............
...*****.......*..............
..............................
........***........******.....
.......**X****.....*X**X*.....
......*******......******.....
.....****X**.......*X**X*.....
........***........******.....
..............................
0 0

Sample Output 

Throw 1
1 2 2 4



题目大意:
  由'*'组成的一块块区域  里面有'x' 如果上下左右四个方向都有相连的x的话 则算一个,
不相连的话 有多少算多少。


思路:
要用到两个DFS  一个用来找'*'组成的区域  一个用来找'x'  




#include<stdio.h>
#include<string.h>
#include<stdlib.h>
char map[55][55];
int num[1000],t,m,n;
int jx []= {1,-1,0,0};
int jy []= {0,0,1,-1};
/**dfs1用来找x**/
void dfs1(int x,int y)
{
    int xx,yy,i;
    map[x][y]='*';///将此点的x换为*  相当于标记  下一次搜索不会再搜到他
    for(i=0; i<4; i++)
    {
        xx=x+jx[i],yy=y+jy[i];
        if(xx>=n||yy>=m||xx<0||yy<0||map[xx][yy]=='*')///边界
            continue;
        if(map[xx][yy]=='X')
            dfs1(xx,yy);
    }
}
/**dfs2用来找'*'区域**/
void dfs2(int x,int y)
{
    int xx,yy,i;
    map[x][y]='.';///将此点由 * 换为 . 相当于标记
    for(i=0; i<4; i++)
    {
        xx=x+jx[i],yy=y+jy[i];
        if(xx>=n||yy>=m||xx<0||yy<0||map[xx][yy]=='.')///边界
            continue;
        if(map[xx][yy]=='X')
        {
            dfs1(xx,yy);
            num[t]++;///哈希
        }
        if(map[xx][yy]=='*')
            dfs2(xx,yy);
    }
}
int cmp (const void *a,const void *b)
{
    return *(int *)a-*(int *)b;
}
int main()
{
    int i,j,k=0;
    while(~scanf("%d%d",&m,&n)&&m&&n)
    {
        memset(num,0,sizeof(num));
        memset(map,'.',sizeof(map));
        t=0;
        for(i=0; i<n; i++)
        {
            scanf("%s",map[i]);
        }
        for(i=0; i<n; i++)
        {
            for(j=0; j<m; j++)
            {
                if(map[i][j]=='*')
                {
                    dfs2(i,j);
                    t++;///表示第几个区域
                }
            }
        }
        /**排序输出**/
        qsort(num,t,sizeof (num[0]),cmp);
        printf("Throw %d\n",++k);
        for(i=0; i<t-1; i++)
            printf("%d ",num[i]);
        printf("%d\n",num[i]);
        printf("\n");
    }
    return 0;
}



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