poj3026
最小生成树，要注意多余的空格（包括x,y那行）
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#include
<
iostream
>
#include
<
cstdio
>
#include
<
cstdlib
>
#include
<
cstring
>
using
namespace
std;
#define
maxn 105
#define
inf 0x3f3f3f3f
struct
Point
{
int
x, y;
} point[maxn], q[maxn
*
maxn];
int
n, m;
bool
map[maxn][maxn];
int
dist[maxn][maxn];
char
st[maxn][maxn];
int
tot;
int
dir[
4
][
2
]
=
{
{
0
,
1
},
{
1
,
0
},
{
-
1
,
0
},
{
0
,
-
1
} };
int
vis[maxn];
int
lowc[maxn];
int
cost[maxn][maxn];
void
input()
{
scanf(
"
%d%d
"
,
&
m,
&
n);
gets(st[
0
]);
for
(
int
i
=
0
; i
<
n; i
++
)
gets(st[i]);
tot
=
1
;
for
(
int
i
=
0
; i
<
n; i
++
)
for
(
int
j
=
0
; j
<
m; j
++
)
{
if
(st[i][j]
==
'
#
'
)
map[i][j]
=
false
;
else
map[i][j]
=
true
;
if
(st[i][j]
==
'
S
'
)
{
point[
0
].x
=
i;
point[
0
].y
=
j;
}
if
(st[i][j]
==
'
A
'
)
{
point[tot].x
=
i;
point[tot].y
=
j;
tot
++
;
}
}
}
bool
ok(Point
&
a)
{
if
(a.x
<
0
||
a.y
<
0
||
a.x
>=
n
||
a.y
>=
m)
return
false
;
return
map[a.x][a.y]
&&
(dist[a.x][a.y]
==
-
1
);
}
void
bfs(Point
&
a)
{
memset(dist,
-
1
,
sizeof
(dist));
int
front, rear;
front
=
rear
=
0
;
q[rear
++
]
=
a;
dist[a.x][a.y]
=
0
;
Point temp;
while
(front
!=
rear)
{
temp
=
q[front
++
];
if
(front
==
maxn
*
maxn)
front
=
0
;
Point b;
for
(
int
i
=
0
; i
<
4
; i
++
)
{
b.x
=
temp.x
+
dir[i][
0
];
b.y
=
temp.y
+
dir[i][
1
];
if
(ok(b))
{
q[rear
++
]
=
b;
if
(rear
==
maxn
*
maxn)
rear
=
0
;
dist[b.x][b.y]
=
dist[temp.x][temp.y]
+
1
;
}
}
}
}
void
make()
{
for
(
int
i
=
0
; i
<
tot; i
++
)
{
bfs(point[i]);
for
(
int
j
=
0
; j
<
tot; j
++
)
cost[i][j]
=
dist[point[j].x][point[j].y];
}
}
int
prim(
int
n)
{
int
i, j, p;
int
minc, res
=
0
;
memset(vis,
0
,
sizeof
(vis));
vis[
0
]
=
1
;
for
(i
=
1
; i
<
n; i
++
)
lowc[i]
=
cost[
0
][i];
for
(i
=
1
; i
<
n; i
++
)
{
minc
=
inf;
p
=
-
1
;
for
(j
=
0
; j
<
n; j
++
)
if
(
0
==
vis[j]
&&
minc
>
lowc[j])
{
minc
=
lowc[j];
p
=
j;
}
if
(inf
==
minc)
return
-
1
;
res
+=
minc;
vis[p]
=
1
;
for
(j
=
0
; j
<
n; j
++
)
if
(
0
==
vis[j]
&&
lowc[j]
>
cost[p][j])
lowc[j]
=
cost[p][j];
}
return
res;
}
int
main()
{
//
freopen("t.txt", "r", stdin);
int
t;
scanf(
"
%d
"
,
&
t);
while
(t
--
)
{
input();
make();
printf(
"
%d\n
"
, prim(tot));
}
return
0
;
}