HDU 1198 Farm Irrigation
/*
并查集！最后判断有几个父亲就是答案了
*/
#include
<
iostream
>
#include
<
set
>
using
namespace
std;
struct
G{
int
left;
int
right;
int
up;
int
down;
};
const
int
MAXN
=
50
;
int
father[MAXN
*
MAXN];
int
m,n;
G g[
11
]
=
{{
1
,
0
,
1
,
0
},{
0
,
1
,
1
,
0
},{
1
,
0
,
0
,
1
},
{
0
,
1
,
0
,
1
},{
0
,
0
,
1
,
1
},{
1
,
1
,
0
,
0
},{
1
,
1
,
1
,
0
},
{
1
,
0
,
1
,
1
},{
1
,
1
,
0
,
1
},{
0
,
1
,
1
,
1
},{
1
,
1
,
1
,
1
}};
void
markSet(
int
m,
int
n){
for
(
int
i
=
0
; i
<
m
*
n; i
++
){
father[i]
=
i;
}
}
int
findSet(
int
x){
if
(father[x]
!=
x)
father[x]
=
findSet(father[x]);
return
father[x];
}
void
merge(
int
x1,
int
y1,
int
x2,
int
y2){
int
fx
=
x1
*
n
+
y1;
//
int
fy
=
x2
*
n
+
y2;
//
fx
=
findSet(fx);
fy
=
findSet(fy);
if
(fx
==
fy){
return
;
}
else
if
(fx
<
fy){
father[fy]
=
fx;
}
else
{
father[fx]
=
fy;
}
}
bool
connect1(
char
ch1,
char
ch2){
if
(g[ch1
-
'
A
'
].right
==
1
&&
g[ch2
-
'
A
'
].left
==
1
)
return
true
;
else
return
false
;
}
bool
connect2(
char
ch1,
char
ch2){
if
(g[ch1
-
'
A
'
].down
==
1
&&
g[ch2
-
'
A
'
].up
==
1
)
return
true
;
else
return
false
;
}
int
main(){
char
map[MAXN][MAXN];
set
<
int
>
s;
while
(cin
>>
m
>>
n){
if
(m
<
0
&&
n
<
0
)
break
;
s.clear();
markSet(m,n);
for
(
int
i
=
0
; i
<
m ; i
++
){
cin
>>
map[i][
0
];
if
(i
!=
0
&&
connect2(map[i
-
1
][
0
],map[i][
0
])){
merge(i,
0
,i
-
1
,
0
);
}
for
(
int
j
=
1
; j
<
n; j
++
){
cin
>>
map[i][j];
if
(connect1(map[i][j
-
1
],map[i][j]))
merge(i,j
-
1
,i,j);
if
(i
!=
0
&&
connect2(map[i
-
1
][j],map[i][j])){
merge(i
-
1
,j,i,j);
}
}
}
for
(
int
i
=
0
; i
<
m
*
n; i
++
)
findSet(i);
for
(
int
i
=
0
; i
<
m
*
n; i
++
)
s.insert(father[i]);
cout
<<
s.size()
<<
endl;
//
用stl的set容器判断是否是连通的
}
return
0
;
}