HDU 1241 DFS

Oil Deposits

 

Problem 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 file 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

 

For each grid, output the number of distinct oil deposits. Two different pockets are part of the same oil deposit if they 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

 

0122

 题意：找出有几部分'@', dfs即可求解

代码：

#include <iostream>using namespace std;int dire[8][2]={{0,1},{0,-1},{1,0},{-1,0},{1,1},{1,-1},{-1,1},{-1,-1}};int a,b;int cnt;//记录总数char map[101][101];//邻接矩阵void dfs(int x,int y)//深搜{int xx,yy,i;for(i=0;i<8;i++)//八个方向寻找{xx=x+dire[i][0];yy=y+dire[i][1];if(xx<0||xx>=a||yy<0||yy>=b)//判断越界continue;if(map[xx][yy]=='*')continue;map[xx][yy]='*';//找到之后，讲'@'变为'*'dfs(xx,yy);}}int main(){int i,j;while(scanf("%d%d",&a,&b)&&(a||b)){cnt=0;for(i=0;i<a;i++)scanf("%s",map[i]);for(i=0;i<a;i++){for(j=0;j<b;j++)if(map[i][j]=='@'){dfs(i,j);cnt++;}}printf("%d\n",cnt);}return 0;}