hdu 1312 Red and Black dfs

简单dfs

#include<iostream>#include<cstring>#include<cstdio>#include<algorithm>#include<vector>#include<cmath>using namespace std;int f[4][2]={0,1,1,0,0,-1,-1,0};char a[21][21];int tmp,n,m;void dfs(int x,int y){    int x1, y1;    for(int i=0;i<4;i++)    {        x1=x+f[i][0];y1=y+f[i][1];        if(x1<m&&x1>=0&&y1<n&&y1>=0&&a[x1][y1]=='.')        {            a[x1][y1]='#';            tmp++;            dfs(x1,y1);            //a[x1][y1]='.';        }    }}int main(){    int x,y;    while(cin>>n>>m)    {        getchar();        if(n==0&&m==0)        break;        for(int i=0;i<m;i++)        for(int j=0;j<n;j++)        {            cin>>a[i][j];            if(a[i][j] == '@')            {x=i;y=j;}        }        tmp=1;        dfs(x,y);        cout<<tmp<<endl;    }}