POJ 1562 Oil Deposit经验教训

Description

The GeoSurvComp geologic survey company is responsible for detecting underground oil deposits. GeoSurvComp works with one large rectangular region of land at a time, and creates a grid that divides the land into numerous square plots. It then analyzes each plot separately, using sensing equipment to determine whether or not the plot contains oil. A plot containing oil is called a pocket. If two pockets are adjacent, then they are part of the same oil deposit. Oil deposits can be quite large and may contain numerous pockets. Your job is to determine how many different oil deposits are contained in a grid.

Input

The input contains one or more grids. Each grid begins with a line containing m and n, the number of rows and columns in the grid, separated by a single space. If m = 0 it signals the end of the input; otherwise 1 <= m <= 100 and 1 <= n <= 100. Following this are m lines of n characters each (not counting the end-of-line characters). Each character corresponds to one plot, and is either `*', representing the absence of oil, or `@', representing an oil pocket.

Output

are adjacent horizontally, vertically, or diagonally. An oil deposit will not contain more than 100 pockets.

Sample Input

1 1
*
3 5
*@*@*
**@**
*@*@*
1 8
@@****@*
5 5 
****@
*@@*@
*@**@
@@@*@
@@**@
0 0

Sample Output

0
1
2
2
其实是一道水题，我却纠结了半个多小时。原因是样例输入数据居然有问题，红色处5 5后跟了一个空格，按理说该直接跟换行，这导致用gets（）输入的话会输入错误数据。

while(scanf("%d%d",&row,&col)&&row)
{
    getchar();
    for(int i=0;i<row;++i)
    {
        gets(Map[i]);
        //printf("This Map[%d],len=%d\n",i,strlen(Map[i]));
        //puts(Map[i]);
    }
}

上面是对本题来说错误的输入代码，其他题目正确。但以后最好小心使用，因为下面的输入代码虽然慢，却十分有效，不容易出错。

while(scanf("%d%d",&row,&col)&&row)
    {
        Read();
        ...
        ...
    }
void Read()
{
    char c;
    for(int i=0;i<row;++i)
    {
        for(int j=0;j<col;++j)
        {
            cin>>c;
            if(c=='*')
            {
                use[i][j]=false;
            }
            else
            {
                use[i][j]=true;
            }
        }
    }
}

以后一定要记住：对换行符输入的处理尽量用C++的输入，不容易出错。

善用C的大神可以无视。