2412 ZOJ Farm Irrigation

/**
因为每一块地，最多只有四个水管的接口，故而可以把每一块土地上，下，左，右，都标记成0或1（0,代表该方向没有接口；1，代表该方向有接口）
DFS(int x, int y){
从第一块开始搜索，如果：
该土地的1.Land[x][y].up=1，则如果和其他土地连通必有，Land[x-1][y].down = 1;(注意：Land[x-1][y]是在Land[x][y]的上方)
2.Land[x][y].left=1，则如果和其他土地连通必有，Land[x][y-1].right = 1;(注意：Land[x][y-1]是在Land[x][y]的左方)
3.Land[x][y].right=1，则如果和其他土地连通必有，Land[x][y+1].left = 1;(注意：Land[x][y+1]是在Land[x][y]的右方)
4.Land[x][y].down=1，则如果和其他土地连通必有，Land[x+1][y].left = 1;(注意：Land[x+1][y]是在Land[x][y]的下方)
}
*/

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;struct Node
{
int data;
int up,down,left,right;
}Land[60][60];
int n,m;
char a;

bool CanGo(int x, int y)
{
if(x>=0 && x<n && y>=0 && y<m)
return true;
else
return false;
}

void DFS(int x, int y)
{
Land[0][0].data = 1;//Land[x][y].data = 0.代表该块土地没有搜索过！Land[x][y] = 1,代表已经走过了；初始时，所有Land[x][y].data = 0;
if(Land[x][y].up == 1 && CanGo(x-1,y) &&!Land[x-1][y].data && Land[x-1][y].down == 1)
{
Land[x-1][y].data = 1;
DFS(x-1, y);
}
if(Land[x][y].left == 1 && CanGo(x, y-1) &&!Land[x][y-1].data && Land[x][y-1].right == 1)
{
Land[x][y-1].data = 1;
DFS(x, y-1);
}
if(Land[x][y].right == 1 && CanGo(x, y+1)&&!Land[x][y+1].data && Land[x][y+1].left == 1)
{
Land[x][y+1].data = 1;
DFS(x, y+1);
}
if(Land[x][y].down == 1 && CanGo(x+1, y)&&!Land[x+1][y].data && Land[x+1][y].up == 1)
{
Land[x+1][y].data = 1;
DFS(x+1, y);
}
return;
}

int main()
{
int i,j;
int ans;
while(cin>>n>>m)
{
if(n<0 || m <0)
break;
for(i = 0; i < n; ++i)
{
for(j = 0; j < m; ++j)
{
cin>>a;
if(a == 'A')
{
Land[i][j].data = 0;
Land[i][j].left = 1;
Land[i][j].up = 1;
Land[i][j].down = Land[i][j].right = 0;
}
else if(a == 'B')
{
Land[i][j].data = 0;
Land[i][j].down = Land[i][j].left = 0;
Land[i][j].right = Land[i][j].up = 1;
}
else if(a == 'C')
{
Land[i][j].data = 0;
Land[i][j].down = Land[i][j].left = 1;
Land[i][j].right = Land[i][j].up = 0;
}
else if(a == 'D')
{
Land[i][j].data = 0;
Land[i][j].down = Land[i][j].right = 1;
Land[i][j].left = Land[i][j].up = 0;
}
else if(a == 'E')
{
Land[i][j].data = 0;
Land[i][j].down = Land[i][j].up = 1;
Land[i][j].left = Land[i][j].right = 0;
}
else if(a == 'F')
{
Land[i][j].data = 0;
Land[i][j].left = Land[i][j].right = 1;
Land[i][j].down = Land[i][j].up = 0;
}
else if(a =='G')
{
Land[i][j].data = 0;
Land[i][j].down = 0;
Land[i][j].left = Land[i][j].right = Land[i][j].up = 1;
}
else if(a == 'H')
{
Land[i][j].data = 0;
Land[i][j].right = 0;
Land[i][j].down = Land[i][j].left = Land[i][j].up = 1;
}
else if(a == 'I')
{
Land[i][j].data = 0;
Land[i][j].down = Land[i][j].left = Land[i][j].right = 1;
Land[i][j].up = 0;
}
else if(a == 'J')
{
Land[i][j].data = 0;
Land[i][j].down = Land[i][j].up = Land[i][j].right = 1;
Land[i][j].left = 0;
}
else if(a == 'K')
{
Land[i][j].data = 0;
Land[i][j].left =Land[i][j].down = Land[i][j].up = Land[i][j].right = 1;
}
}
}
ans = 0;
for(i = 0; i < n; ++i)
{
for(j = 0; j < m; ++j)
{
if(!Land[i][j].data)
{
DFS(i, j);
ans++;
}
}
}
cout<<ans<<endl;
}
return 0;
}