poj1562 Oil Deposits(DFS)

Oil Deposits

Time Limit: 1000MS Memory Limit: 10000KTotal Submissions: 13148 Accepted: 7166

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

0122

Source

Mid-Central USA 1997

#include<stdio.h>#include<iostream>#include<algorithm>#include<string.h>using namespace std;int m,n;char map[105][105];void dfs(int x,int y){//现在的位置是(x,y) map[x][y]='*';//将现在的位置替换为.//循环遍历移动8个方向 for(int dx=-1;dx<=1;dx++){//向x方向移动x,向y方向移动y,移动结果是(nx,ny) for(int dy=-1;dy<=1;dy++){int nx=x+dx;int ny=dy+y;//判断（nx,ny）是否在院子里，以及是否有积水 if(nx>=0&&nx<n&&ny>=0&&ny<m&&map[nx][ny]=='@')dfs(nx,ny);}}}void solve(){int i,j;int ans=0;for(i=0;i<n;i++){for(j=0;j<m;j++){if(map[i][j]=='@'){//从有水的地方开始dfs dfs(i,j);ans++;}}}printf("%d\n",ans);}int main(){int i,j;while(scanf("%d%d",&n,&m)!=EOF&&(m||n)){/*getchar();//在这多加了一个getchar(),让我WA了一上午！！！ for(i=1;i<=n;i++){//getchar();for(j=1;j<=m;j++){scanf("%c",&map[i][j]);}}*/for(i=0;i<n;i++)scanf("%s",map[i]);solve();}return 0;}