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Regler
Advent of Code 2024
Commits
069f0bfe
Commit
069f0bfe
authored
5 months ago
by
Felix Agner
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optimized a bit
parent
c2e7713a
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Changes
1
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1 changed file
day 20/day_20_felix.cpp
+43
-55
43 additions, 55 deletions
day 20/day_20_felix.cpp
with
43 additions
and
55 deletions
day 20/day_20_felix.cpp
+
43
−
55
View file @
069f0bfe
...
@@ -21,8 +21,7 @@ coord START;
...
@@ -21,8 +21,7 @@ coord START;
coord
END
;
coord
END
;
int
N
,
M
=
0
;
int
N
,
M
=
0
;
array
<
array
<
bool
,
145
>
,
145
>
IS_WALL
=
{
true
};
array
<
array
<
bool
,
145
>
,
145
>
IS_WALL
=
{
true
};
map
<
coord
,
ll
>
TO_COME
;
vector
<
coord
>
FORWARD_PATH
;
map
<
coord
,
ll
>
TO_GO
;
void
parse_input
()
{
void
parse_input
()
{
string
line
;
string
line
;
...
@@ -55,70 +54,60 @@ void parse_input() {
...
@@ -55,70 +54,60 @@ void parse_input() {
}
}
bool
in_bounds
(
coord
u
)
{
bool
in_bounds
(
coord
u
)
{
return
u
.
first
>=
0
&&
u
.
first
<
M
&&
u
.
second
>=
0
&&
u
.
second
<
N
;
bool
in
=
u
.
first
>=
0
&&
u
.
first
<
M
&&
u
.
second
>=
0
&&
u
.
second
<
N
;
return
in
&&
!
IS_WALL
[
u
.
first
][
u
.
second
];
}
}
vector
<
coord
>
neighbors
(
coord
u
)
{
coord
move
(
coord
u
,
char
d
)
{
vector
<
coord
>
n
=
{
if
(
d
==
'N'
)
return
{
u
.
first
-
1
,
u
.
second
};
{
u
.
first
-
1
,
u
.
second
},
if
(
d
==
'S'
)
return
{
u
.
first
+
1
,
u
.
second
};
{
u
.
first
+
1
,
u
.
second
},
if
(
d
==
'W'
)
return
{
u
.
first
,
u
.
second
-
1
};
{
u
.
first
,
u
.
second
-
1
},
if
(
d
==
'E'
)
return
{
u
.
first
,
u
.
second
+
1
};
{
u
.
first
,
u
.
second
+
1
}
return
{
-
1
,
-
1
};
};
return
n
;
}
}
vector
<
pair
<
coord
,
int
>>
cheat_neighbors
(
coord
u
,
int
cheat_length
)
{
coord
next
(
coord
u
,
array
<
array
<
bool
,
145
>
,
145
>
&
visited
)
{
vector
<
pair
<
coord
,
int
>>
nlist
;
coord
n
=
move
(
u
,
'N'
);
if
(
in_bounds
(
n
)
&&
!
visited
[
n
.
first
][
n
.
second
])
return
n
;
// grab all squares within distance cheat_length that are not in a wall
n
=
move
(
u
,
'S'
);
for
(
int
i
=
-
cheat_length
;
i
<=
cheat_length
;
i
++
)
{
if
(
in_bounds
(
n
)
&&
!
visited
[
n
.
first
][
n
.
second
])
return
n
;
for
(
int
j
=
-
cheat_length
+
abs
(
i
);
j
<=
cheat_length
-
abs
(
i
);
j
++
)
{
n
=
move
(
u
,
'W'
);
coord
n
=
{
u
.
first
+
i
,
u
.
second
+
j
};
if
(
in_bounds
(
n
)
&&
!
visited
[
n
.
first
][
n
.
second
])
return
n
;
if
(
!
in_bounds
(
n
)
||
IS_WALL
[
n
.
first
][
n
.
second
])
continue
;
n
=
move
(
u
,
'E'
);
int
cost
=
abs
(
i
)
+
abs
(
j
);
if
(
in_bounds
(
n
)
&&
!
visited
[
n
.
first
][
n
.
second
])
return
n
;
return
{
-
1
,
-
1
};
if
(
cost
<=
cheat_length
)
nlist
.
push_back
({
n
,
cost
});
}
}
}
return
nlist
;
int
dist
(
coord
u
,
coord
v
)
{
return
abs
(
u
.
first
-
v
.
first
)
+
abs
(
u
.
second
-
v
.
second
);
}
}
vector
<
coord
>
bfs
(
coord
start
)
{
map
<
coord
,
ll
>
bfs
(
coord
start
)
{
queue
<
tuple
<
ll
,
coord
>>
q
;
q
.
push
({
0
,
start
});
array
<
array
<
bool
,
145
>
,
145
>
visited
=
{
false
};
array
<
array
<
bool
,
145
>
,
145
>
visited
=
{
false
};
ll
n_cheats
=
0
;
map
<
coord
,
ll
>
costs
;
costs
[
start
]
=
0
;
visited
[
start
.
first
][
start
.
second
]
=
true
;
visited
[
start
.
first
][
start
.
second
]
=
true
;
vector
<
coord
>
path
=
{
start
};
coord
curr
=
next
(
start
,
visited
);
while
(
!
q
.
empty
())
{
while
(
curr
!=
END
)
{
auto
[
c
,
pos
]
=
q
.
front
();
q
.
pop
();
visited
[
curr
.
first
][
curr
.
second
]
=
true
;
path
.
push_back
(
curr
);
for
(
coord
n
:
neighbors
(
pos
))
if
(
in_bounds
(
n
)
&&
!
IS_WALL
[
n
.
first
][
n
.
second
]
&&
!
visited
[
n
.
first
][
n
.
second
])
{
curr
=
next
(
curr
,
visited
);
q
.
push
({
c
+
1
,
n
});
costs
[
n
]
=
c
+
1
;
visited
[
n
.
first
][
n
.
second
]
=
true
;
}
}
}
path
.
push_back
(
END
);
return
costs
;
return
path
;
}
}
ll
n_cheats
(
int
cheat_distance
,
ll
baseline
)
{
ll
n_cheats
(
int
cheat_distance
,
int
improvement_goal
)
{
ll
n_cheats
=
0
;
ll
n_cheats
=
0
;
for
(
auto
[
pos
,
cost
]
:
TO_COME
)
if
(
cost
<
baseline
)
{
for
(
int
i
=
0
;
i
<
FORWARD_PATH
.
size
()
-
improvement_goal
;
i
++
)
{
for
(
auto
[
cheat_pos
,
cheat_cost
]
:
cheat_neighbors
(
pos
,
cheat_distance
)
)
{
for
(
int
j
=
i
+
improvement_goal
;
j
<
FORWARD_PATH
.
size
();
j
++
)
{
i
f
(
TO_GO
[
cheat_pos
]
+
cost
+
cheat_cost
<=
baseline
)
{
i
nt
d
=
dist
(
FORWARD_PATH
[
i
],
FORWARD_PATH
[
j
]);
n_cheats
++
;
if
(
d
>
cheat_distance
)
j
+=
max
(
d
-
cheat_distance
-
1
,
0
)
;
}
else
if
(
j
-
i
-
d
>=
improvement_goal
)
n_cheats
++
;
}
}
}
}
return
n_cheats
;
return
n_cheats
;
...
@@ -127,20 +116,19 @@ ll n_cheats(int cheat_distance, ll baseline) {
...
@@ -127,20 +116,19 @@ ll n_cheats(int cheat_distance, ll baseline) {
int
main
(
int
argc
,
char
*
argv
[])
{
int
main
(
int
argc
,
char
*
argv
[])
{
for
(
int
i
=
0
;
i
<
argc
;
i
++
)
if
(
string
(
argv
[
i
])
==
"-d"
)
DEBUG
=
true
;
for
(
int
i
=
0
;
i
<
argc
;
i
++
)
if
(
string
(
argv
[
i
])
==
"-d"
)
DEBUG
=
true
;
if
(
DEBUG
)
cout
<<
"Reading data..."
<<
endl
;
parse_input
();
parse_input
();
FORWARD_PATH
=
bfs
(
START
);
TO_COME
=
bfs
(
START
);
if
(
DEBUG
)
cout
<<
"Data read."
<<
endl
;
TO_GO
=
bfs
(
END
);
ll
baseline
=
TO_COME
[
END
];
if
(
DEBUG
)
{
if
(
DEBUG
)
{
cout
<<
"Baseline: "
<<
baseline
<<
endl
;
cout
<<
"Baseline: "
<<
FORWARD_PATH
.
size
()
<<
endl
;
}
}
ll
part1
=
n_cheats
(
2
,
baseline
-
100
);
ll
part1
=
n_cheats
(
2
,
100
);
cout
<<
"Part 1: "
<<
part1
<<
endl
;
cout
<<
"Part 1: "
<<
part1
<<
endl
;
ll
part2
=
n_cheats
(
20
,
baseline
-
100
);
ll
part2
=
n_cheats
(
20
,
100
);
cout
<<
"Part 2: "
<<
part2
<<
endl
;
cout
<<
"Part 2: "
<<
part2
<<
endl
;
return
0
;
return
0
;
...
...
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