poj3984
简单题
View Code
#include
<
iostream
>
#include
<
cstdio
>
#include
<
cstdlib
>
#include
<
cstring
>
using
namespace
std;
#define
maxn 10
struct
Point
{
int
x, y;
}q[maxn
*
maxn], stk[maxn
*
maxn];
int
map[maxn][maxn];
int
cost[maxn][maxn];
int
from[maxn][maxn];
int
dir[
4
][
2
]
=
{
{
1
,
0
},
{
0
,
1
},
{
-
1
,
0
},
{
0
,
-
1
} };
bool
ok(Point
&
a)
{
if
(a.x
<
0
||
a.y
<
0
||
a.x
>=
5
||
a.y
>=
5
)
return
false
;
return
!
map[a.x][a.y]
&&
(cost[a.x][a.y]
==
-
1
);
}
int
main()
{
//
freopen("t.txt", "r", stdin);
for
(
int
i
=
0
; i
<
5
; i
++
)
for
(
int
j
=
0
; j
<
5
; j
++
)
scanf(
"
%d
"
,
&
map[i][j]);
int
l
=
0
;
int
r
=
1
;
q[
0
].x
=
0
;
q[
0
].y
=
0
;
memset(cost,
-
1
,
sizeof
(cost));
cost[
0
][
0
]
=
0
;
while
(l
!=
r)
{
for
(
int
i
=
0
; i
<
4
; i
++
)
{
Point p;
p.x
=
q[l].x
+
dir[i][
0
];
p.y
=
q[l].y
+
dir[i][
1
];
if
(ok(p))
{
q[r
++
]
=
p;
from[p.x][p.y]
=
i;
cost[p.x][p.y]
=
cost[q[l].x][q[l].y]
+
1
;
}
}
l
++
;
}
int
top
=
0
;
Point a;
a.x
=
4
;
a.y
=
4
;
int
t;
while
(
!
(a.x
==
0
&&
a.y
==
0
))
{
stk[top
++
]
=
a;
t
=
from[a.x][a.y];
a.x
-=
dir[t][
0
];
a.y
-=
dir[t][
1
];
}
printf(
"
(0, 0)\n
"
);
while
(top
--
)
printf(
"
(%d, %d)\n
"
, stk[top].x, stk[top].y);
return
0
;
}