POJ 2386 Lake Counting (Dfs-floodfill)

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POJ 2386 Topic

Given a n*m map, ' W ' indicates stagnant water, '. ' Indicates the open space, the water is eight connected, ask how many water blocks. Analysis

The topic is a typical solution to the number of pieces of the basic problem, the idea is to use floodfill (diffuse water filling method), scan a picture, each encounter a ' W ' counter plus one, and deep search or wide search to the adjacent ' W ' fill as '. ' Until there is no water on the chart.
pay attention to the input of the string: either use CIN or use GetChar () to handle the line break. Code

#include <iostream> #include <cstdio> using namespace std;
Char field[1001][1001];
int n,m;
    void Dfs_floodfill (int x,int y)//floodfill {field[x][y]= '. ';
        for (int dx=-1;dx<=1;dx++) for (int dy=-1;dy<=1;dy++) {int xx=x+dx;
        int yy=y+dy; if (xx>=1&&xx<=n&&yy>=1&&yy<=m&&field[xx][yy]== ' W ') DFS_floodfill (
    XX,YY);
    }} int main () {int i,j,ans;
        while (scanf ("%d%d", &n,&m)!=eof) {GetChar ();//Note that there are line breaks before entering the map, it is important.
            for (i=1;i<=n;i++) {for (j=1;j<=m;j++) scanf ("%c", &field[i][j]);
        GetChar ();
        } ans=0;
                    for (i=1;i<=n;i++) for (j=1;j<=m;j++) if (field[i][j]== ' W ') {
                    Dfs_floodfill (I,J);
                ans++;
    } cout<<ans<<endl;
} return 0;
 }