Extended Lights Out--ZOJ 1354
1、解题思路：贪心、枚举、位运算。
2、注意事项：
位运算：注意^ 、^、<<；
递归：注意剪枝；
3、实现方法：
1
#include
<
iostream
>
2
using
namespace
std;
3
#define
ROW 5
4
#define
COL 6
5
6
bool
isOK;
7
8
int
press[
30
]
=
{
9
06040000000
,
07020000000
,
03410000000
,
01604000000
,
0702000000
,
0301000000
,
10
04060400000
,
02070200000
,
01034100000
,
0416040000
,
0207020000
,
0103010000
,
11
040604000
,
020702000
,
010341000
,
04160400
,
02070200
,
01030100
,
12
0406040
,
0207020
,
0103410
,
041604
,
020702
,
010301
,
13
04060
,
02070
,
01034
,
0416
,
0207
,
0103
14
};
15
16
int
pressing[
30
]
=
{
17
04000000000
,
02000000000
,
01000000000
,
0400000000
,
0200000000
,
0100000000
,
18
040000000
,
020000000
,
010000000
,
04000000
,
02000000
,
01000000
,
19
0400000
,
0200000
,
0100000
,
040000
,
020000
,
010000
,
20
04000
,
02000
,
01000
,
0400
,
0200
,
0100
,
21
040
,
020
,
010
,
04
,
02
,
01
22
};
23
24
int
Init()
25
{
26
int
i,j,n,data
=
0
;
27
for
(i
=
0
;i
<
ROW;i
++
)
28
{
29
for
(j
=
0
;j
<
COL;j
++
)
30
{
31
cin
>>
n;
32
data
<<=
1
;
33
data
+=
n;
34
}
35
}
36
return
data;
37
}
38
39
void
Print(
int
data)
40
{
41
int
i,j;
42
for
(i
=
0
;i
<
ROW;i
++
)
43
{
44
for
(j
=
0
;j
<
COL;j
++
)
45
{
46
if
( (data
&
pressing[i
*
COL
+
j])
==
0
)
47
cout
<<
0
;
48
else
49
cout
<<
1
;
50
if
( j
<
COL
-
1
)
51
cout
<<
'
'
;
52
}
53
cout
<<
endl;
54
}
55
}
56
57
void
Search(
int
data,
int
preState)
58
{
59
int
i,j;
60
for
(i
=
1
;i
<
ROW;i
++
)
61
{
62
for
(j
=
0
;j
<
COL;j
++
)
63
{
64
if
( (data
&
pressing[(i
-
1
)
*
COL
+
j])
!=
0
)
65
{
66
data
^=
press[i
*
COL
+
j];
67
preState
+=
pressing[i
*
COL
+
j];
68
}
69
}
70
}
71
if
(data
==
0
)
72
{
73
Print(preState);
74
isOK
=
true
;
75
}
76
}
77
78
void
Do(
int
data,
int
x,
int
preState)
79
{
80
//
找到解
81
if
( isOK )
82
{
83
return
;
84
}
85
Search(data,preState);
86
//
遍历完第一行
87
if
( x
==
COL )
88
return
;
89
Do(data,x
+
1
,preState);
90
Do(data
^
press[x],x
+
1
,preState
^
pressing[x]);
91
}
92
93
int
main()
94
{
95
int
i,m;
96
cin
>>
m;
97
int
data;
98
for
(i
=
1
;i
<=
m;i
++
)
99
{
100
cout
<<
"
PUZZLE #
"
<<
i
<<
endl;
101
data
=
Init();
102
isOK
=
false
;
103
Do(data,
0
,
0
);
104
}
105
return
0
;
106
}