poj1321
简单题
View Code
#include
<
iostream
>
#include
<
cstdio
>
#include
<
cstdlib
>
#include
<
cstring
>
using
namespace
std;
#define
maxn 10
bool
row[maxn], col[maxn];
bool
map[maxn][maxn];
int
ans, n, m;
void
input()
{
char
ch;
memset(map,
0
,
sizeof
(map));
getchar();
for
(
int
i
=
0
; i
<
n; i
++
)
{
for
(
int
j
=
0
; j
<
n; j
++
)
{
ch
=
getchar();
if
(ch
==
'
#
'
)
map[i][j]
=
true
;
else
map[i][j]
=
false
;
}
getchar();
}
}
void
dfs(
int
pos,
int
a)
{
if
(a
==
m)
{
ans
++
;
return
;
}
while
(pos
<
n
*
n)
{
int
x
=
pos
/
n;
int
y
=
pos
%
n;
if
(map[x][y]
&&
!
row[x]
&&
!
col[y])
{
row[x]
=
col[y]
=
true
;
dfs(pos
+
1
, a
+
1
);
row[x]
=
col[y]
=
false
;
}
pos
++
;
}
}
int
main()
{
//
freopen("t.txt", "r", stdin);
while
(scanf(
"
%d%d
"
,
&
n,
&
m),
!
(n
==
-
1
&&
m
==
-
1
))
{
input();
memset(row,
0
,
sizeof
(row));
memset(col,
0
,
sizeof
(col));
ans
=
0
;
dfs(
0
,
0
);
printf(
"
%d\n
"
, ans);
}
return
0
;
}