POJ 1856 Sea Battle (bfs,dfs)
题意：寻找相连的区域，八个方向都要找，判断这个区域是否为矩形。
这题写得太悲剧了，写哭了，bfs写完超时，dfs写完还超时...........最后才发现是在输入处理上出了问题....哎，啥都不说了....都在代码里了........
bfs:
#include
<
iostream
>
#include
<
cstdio
>
#include
<
algorithm
>
#include
<
memory.h
>
#include
<
cmath
>
#include
<
vector
>
using
namespace
std;
const
int
BORDER
=
(
1
<<
26
)
-
1
;
#define
MAXN 1010
#define
INF 0x7ffffff
#define
_clr(x,y) memset(x,y,sizeof(x))
#define
_add(x) ((++x)&BORDER)
#define
_in(x) scanf("%d",&x)
#define
_out(x) printf("%d\n",x)
#define
_min(m,v) m<v?m:v
#define
_max(m,v) m>v?m:v
#define
_set_que(q,i,a,b) {q[i].x=a;q[i].y=b;}
#define
_set_node(n,a,b) {n.x=a;n.y=b;}
struct
NODE{
int
x,y;
}que[BORDER
+
5
],node[MAXN
*
MAXN];
int
index;
int
direct[
8
][
2
]
=
{{
-
1
,
-
1
},{
-
1
,
0
},{
-
1
,
1
},{
0
,
1
},
{
1
,
1
},{
1
,
0
},{
1
,
-
1
},{
0
,
-
1
}};
int
direct1[
4
][
2
]
=
{{
0
,
1
},{
0
,
-
1
},{
1
,
0
},{
-
1
,
0
}};
int
visit[MAXN][MAXN];
char
arr[MAXN][MAXN];
int
n,m,en,st,ans,minx,miny,maxx,maxy;
inline
bool
_is(
const
int
&
x,
const
int
&
y)
{
if
(x
<
0
||
x
>=
n)
return
false
;
if
(y
<
0
||
y
>=
m)
return
false
;
return
true
;
}
inline
void
_max_min(
const
int
&
a,
const
int
&
b)
{
minx
=
_min(minx,a);
miny
=
_min(miny,b);
maxx
=
_max(maxx,a);
maxy
=
_max(maxy,b);
}
int
init()
{
en
=
1
;
st
=
0
;
ans
=
0
;
index
=
0
;
_clr(visit,
0
);
return
0
;
}
int
bfs(
const
int
&
px,
const
int
&
py)
{
int
x,y,i,j,tmp,a,b,sum;
/*
init
*/
en
=
1
;
st
=
sum
=
0
;
visit[px][py]
=
1
;
minx
=
INF;
miny
=
INF;
maxx
=
-
1
;
maxy
=
-
1
;
_set_que(que,
0
,px,py);
while
(st
<
en)
{
a
=
que[st].x;
b
=
que[st].y;
_max_min(a,b);
++
sum;
_add(st);
for
(i
=
0
; i
<
8
;
++
i)
{
x
=
a
+
direct[i][
0
];
y
=
b
+
direct[i][
1
];
if
(_is(x,y)
&&
arr[x][y]
==
'
#
'
&&
!
visit[x][y])
{
visit[x][y]
=
1
;
_set_que(que,en,x,y);
_add(en);
}
}
}
tmp
=
(maxx
-
minx
+
1
)
*
(maxy
-
miny
+
1
);
if
(tmp
==
sum)
return
1
;
else
return
0
;
}
int
main()
{
int
i,j,tmp;
char
str[MAXN];
while
(scanf(
"
%d%d
"
,
&
n,
&
m))
{
if
(
!
n
&&
!
m)
break
;
init();
gets(str);
for
(i
=
0
; i
<
n;
++
i)
scanf(
"
%s
"
,arr[i]);
for
(i
=
0
; i
<
n;
++
i)
{
for
(j
=
0
; j
<
m;
++
j)
if
(arr[i][j]
==
'
#
'
&&
!
visit[i][j])
{
tmp
=
bfs(i,j);
if
(tmp)
++
ans;
else
{
ans
=
-
1
;
break
;
}
}
if
(ans
==
-
1
)
break
;
}
if
(ans
==
-
1
)
printf(
"
Bad placement.\n
"
);
else
printf(
"
There are %d ships.\n
"
,ans);
}
return
0
;
}
#include
<
iostream
>
#include
<
cstdio
>
#include
<
algorithm
>
#include
<
memory.h
>
#include
<
cmath
>
#include
<
vector
>
using
namespace
std;
const
int
BORDER
=
(
1
<<
26
)
-
1
;
#define
MAXN 1010
#define
INF 0x7ffffff
#define
_clr(x,y) memset(x,y,sizeof(x))
#define
_add(x) ((++x)&BORDER)
#define
_in(x) scanf("%d",&x)
#define
_out(x) printf("%d\n",x)
#define
_min(m,v) m<v?m:v
#define
_max(m,v) m>v?m:v
#define
_set_que(q,i,a,b) {q[i].x=a;q[i].y=b;}
#define
_set_node(n,a,b) {n.x=a;n.y=b;}
struct
NODE{
int
x,y;
}que[BORDER
+
5
],node[MAXN
*
MAXN];
int
index;
int
direct[
8
][
2
]
=
{{
-
1
,
-
1
},{
-
1
,
0
},{
-
1
,
1
},{
0
,
1
},
{
1
,
1
},{
1
,
0
},{
1
,
-
1
},{
0
,
-
1
}};
int
direct1[
4
][
2
]
=
{{
0
,
1
},{
0
,
-
1
},{
1
,
0
},{
-
1
,
0
}};
int
visit[MAXN][MAXN];
char
arr[MAXN][MAXN];
int
n,m,en,st,ans,minx,miny,maxx,maxy,sum;
inline
bool
_is(
const
int
&
x,
const
int
&
y)
{
if
(x
<
0
||
x
>=
n)
return
false
;
if
(y
<
0
||
y
>=
m)
return
false
;
return
true
;
}
inline
void
_max_min(
const
int
&
a,
const
int
&
b)
{
minx
=
_min(minx,a);
miny
=
_min(miny,b);
maxx
=
_max(maxx,a);
maxy
=
_max(maxy,b);
}
int
init()
{
en
=
1
;
st
=
0
;
ans
=
0
;
index
=
0
;
_clr(visit,
0
);
return
0
;
}
int
dfs(
const
int
&
x,
const
int
&
y)
{
int
a,b;
visit[x][y]
=
1
;
++
sum;
_max_min(x,y);
for
(
int
i
=
0
; i
<
8
;
++
i)
{
a
=
x
+
direct[i][
0
];
b
=
y
+
direct[i][
1
];
if
(_is(a,b)
&&
arr[a][b]
==
'
#
'
&&
!
visit[a][b])
dfs(a,b);
}
return
0
;
}
int
main()
{
int
i,j,tmp;
char
str[MAXN];
while
(scanf(
"
%d%d
"
,
&
n,
&
m))
{
if
(
!
n
||
!
m)
return
0
;
init();
for
(i
=
0
; i
<
n;
++
i)
{
scanf(
"
%s
"
,arr[i]);
}
for
(i
=
0
; i
<
n;
++
i)
for
(j
=
0
; j
<
m;
++
j)
{
if
(arr[i][j]
==
'
#
'
&&
!
visit[i][j])
{
maxx
=
maxy
=
-
1
;
minx
=
miny
=
INF;
sum
=
0
;
dfs(i,j);
if
( sum
==
(maxx
-
minx
+
1
)
*
(maxy
-
miny
+
1
) )
++
ans;
else
{
ans
=
-
1
;
break
;
}
}
if
(ans
==
-
1
)
break
;
}
if
(ans
==
-
1
)
printf(
"
Bad placement.\n
"
);
else
printf(
"
There are %d ships.\n
"
,ans);
}
return
0
;
}