hoj1078
记忆化搜索，使用dfs，从0,0点开始，把每个点对应的剩下路程所能得到的最大值存入f数组。
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#include
<
iostream
>
#include
<
cstdio
>
#include
<
cstdlib
>
#include
<
cstring
>
#include
<
vector
>
#include
<
cmath
>
#include
<
queue
>
using
namespace
std;
#define
maxn 105
int
map[maxn][maxn];
int
f[maxn][maxn];
int
ans, fans, n, m;
int
dir[
4
][
2
]
=
{
{
1
,
0
},
{
0
,
1
},
{
-
1
,
0
},
{
0
,
-
1
} };
void
input()
{
for
(
int
i
=
0
; i
<
n; i
++
)
for
(
int
j
=
0
; j
<
n; j
++
)
scanf(
"
%d
"
,
&
map[i][j]);
}
bool
ok(
int
x,
int
y)
{
if
(x
<
0
||
y
<
0
||
x
>=
n
||
y
>=
n)
return
false
;
return
true
;
}
int
dfs(
int
x,
int
y)
{
if
(f[x][y]
!=
-
1
)
return
f[x][y];
int
ans
=
0
;
for
(
int
i
=
0
; i
<
4
; i
++
)
for
(
int
j
=
1
; j
<=
m; j
++
)
{
if
(
!
ok(x
+
dir[i][
0
]
*
j, y
+
dir[i][
1
]
*
j))
break
;
if
(map[x
+
dir[i][
0
]
*
j][y
+
dir[i][
1
]
*
j]
>
map[x][y])
{
int
temp
=
dfs(x
+
dir[i][
0
]
*
j, y
+
dir[i][
1
]
*
j);
if
(temp
>
ans)
ans
=
temp;
}
}
f[x][y]
=
map[x][y]
+
ans;
return
f[x][y];
}
int
main()
{
//
freopen("D:\\t.txt", "r", stdin);
while
(scanf(
"
%d%d
"
,
&
n,
&
m)
!=
EOF)
{
if
(n
==
-
1
&&
m
==
-
1
)
break
;
input();
memset(f,
-
1
,
sizeof
(f));
printf(
"
%d\n
"
, dfs(
0
,
0
));
}
return
0
;
}