hdu1241 dfs

链接改天再补 杭电又崩了。。。

题意：求“@”组成了多少个联通区域，每个点的8个方向都认为是相连的

思路：对每一个点进行搜索 当Map == @ && vis == 0 时 可进入搜索 每次进入搜索时 ans++ 搜索时将该联通区域所有的点标记 8个方向搜

AC代码：

#include "iostream"
#include "string.h"
#include "stack"
#include "queue"
#include "map"
#include "algorithm"
#include "stdio.h"
#include "math.h"
#define ll long long
#define mem(a) memset(a,0,sizeof(a))
#define max(a,b) a > b ? a : b
#define min(a,b) a < b ? a : b

using namespace std;

int d[8][2] = {{0,1},{1,0},{0,-1},{-1,0},{-1,1},{1,1},{1,-1},{-1,-1}};
bool vis[1005][1005];
bool Map[1005][1005];

struct Node
{
    int xx,yy;
};

void Dfs(int x,int y)
{
    stack<Node>S;
    Node now,next;
    now.xx = x;
    now.yy = y;
    vis[x][y] = 1;
    S.push(now);

    while(!S.empty())
    {
        now = S.top();
        S.pop();

        for(int i=0; i<8; i++)
        {
            next.xx = now.xx + d[i][0];
            next.yy = now.yy + d[i][1];

            if(Map[next.xx][next.yy] && !vis[next.xx][next.yy])
            {
                vis[next.xx][next.yy] = 1;
                S.push(next);
            }
        }
    }
}

int main()
{
    int n,m,i,j,ans;
    char c;
    while(scanf("%d%d",&m,&n)&&(m||n))
    {
        mem(vis);
        mem(Map);
        ans = 0;
        for(i=1; i<=m; i++)
            for(j=1; j<=n; j++)
            {
                cin>>c;
                if(c=='@')
                    Map[i][j] = 1;
                if(c=='*')
                    Map[i][j] = 0;
            }
        for(i=1; i<=m; i++)
            for(j=1; j<=n; j++)
            {
                if(Map[i][j] && !vis[i][j])
                {
                    ans++;
                    Dfs(i,j);
                }
            }
        printf("%d
",ans);
    }
    return 0;
}