左偏树
思想很好理解，代码很好写
我偷懒想用动态内存，省点代码，结果悲剧了
merge两个左偏树以后内存的维护边的异常混乱，无奈不维护内存了，直接makeNULL();
C++唯一让我不爽的地方就是动态内存的维护太费劲了。
HDU 1512
1
#include
<
iostream
>
2
#include
<
cstring
>
3
#include
<
cstdio
>
4
#include
<
cassert
>
5
using
namespace
std;
6
#define
CMP(a, b) ((a) > (b))
7
#define
DIST(v) ((v == NULL) ? -1 : (v->dist))
8
//
must be careful when clear after merge
9
//
because of the pointer could not be NULL
10
//
especially when use new
11
template
<
typename T
>
12
class
leftist_tree
13
{
14
private
:
15
class
node
16
{
17
public
:
18
T v;
19
int
dist;
20
node
*
rr,
*
ll;
21
node(){rr
=
ll
=
NULL; dist
=
0
;}
22
node(T v){
this
->
v
=
v; rr
=
ll
=
NULL;dist
=
0
;}
23
};
24
node
*
root;
25
int
s;
26
node
*
merge(node
*
&
left, node
*
&
right)
27
{
28
if
(left
==
NULL)
return
right;
29
if
(right
==
NULL)
return
left;
30
if
(CMP(right
->
v, left
->
v)) swap(left, right);
31
left
->
rr
=
merge(left
->
rr, right);
32
if
(DIST(left
->
rr)
>
DIST(left
->
ll)) swap(left
->
ll, left
->
rr);
33
left
->
dist
=
DIST(left
->
rr)
+
1
;
34
return
left;
35
}
36
void
clear(node
*
root)
37
{
38
if
(root
==
NULL)
return
;
39
clear(root
->
ll);
40
clear(root
->
rr);
41
delete root;
42
root
=
NULL;
43
}
44
public
:
45
leftist_tree(){root
=
NULL;s
=
0
;}
46
~
leftist_tree(){clear(root);}
47
void
push(T v)
48
{
49
node
*
newNode
=
new
node(v);
50
root
=
merge(newNode, root);
51
s
++
;
52
}
53
void
clear(){clear(root);}
54
int
size(){
return
this
->
s;}
55
T top(){
return
root
->
v;}
56
void
pop()
57
{
58
node
*
tmp
=
root;
59
root
=
merge(root
->
ll, root
->
rr);
60
delete tmp;
61
s
--
;
62
}
63
void
merge(leftist_tree
<
T
>&
tree)
64
{
65
this
->
root
=
merge(root, tree.root);
66
s
+=
tree.s;
67
tree.root
=
NULL;
68
}
69
void
makeNULL(){root
=
NULL;}
70
};
71
72
const
int
N
=
100001
;
73
leftist_tree
<
int
>
tree[N];
74
int
father[N], rank[N];
75
int
find_set(
int
x)
76
{
77
return
father[x]
=
father[x]
==
x
?
x :find_set(father[x]);
78
}
79
bool
union_set(
int
x,
int
y)
80
{
81
if
(x
!=
y)
82
{
83
if
(rank[x]
<
rank[y]) father[x]
=
y;
84
else
85
{
86
rank[x]
+=
rank[x]
==
rank[y];
87
father[y]
=
x;
88
}
89
return
false
;
90
}
91
return
true
;
92
}
93
bool
link_set(
int
x,
int
y)
94
{
95
return
union_set(find_set(x), find_set(y));
96
}
97
98
void
initialize(
int
n)
99
{
100
for
(
int
i
=
1
;i
<=
n;i
++
)
101
{
102
rank[i]
=
0
;
103
father[i]
=
i;
104
}
105
}
106
int
main()
107
{
108
int
n, m, s, a, b;
109
while
(scanf(
"
%d
"
,
&
n)
==
1
)
110
{
111
for
(
int
i
=
1
;i
<=
n;i
++
)
112
{
113
tree[i].clear();
114
scanf(
"
%d
"
,
&
s);
115
tree[i].push(s);
116
}
117
initialize(n);
118
scanf(
"
%d
"
,
&
m);
119
while
(m
--
)
120
{
121
scanf(
"
%d %d
"
,
&
a,
&
b);
122
int
fa
=
find_set(a), fb
=
find_set(b);
123
if
(fa
==
fb) puts(
"
-1
"
);
124
else
125
{
126
link_set(fa, fb);
127
int
va
=
tree[fa].top();
128
tree[fa].pop();tree[fa].push(va
/
2
);
129
int
vb
=
tree[fb].top();
130
tree[fb].pop();tree[fb].push(vb
/
2
);
131
if
(fa
==
find_set(fa))
132
tree[fa].merge(tree[fb]);
133
else
134
tree[fb].merge(tree[fa]);
135
printf(
"
%d\n
"
, tree[find_set(fa)].top());
136
}
137
}
138
}
139
return
0
;
140
}
赤裸裸的左偏树合并操作。第一次写比较搓……
05年论文里的题目没有看懂，太弱了，还要继续加油呀！省赛一等奖，四省赛一等奖！