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斐波那契堆上的减键和删除节点操作

提示
  1. 减小键值:在斐波那契堆中,减小键值操作包括选择节点 x,将其键值减小到一个较低的值 k。如果 x 的父节点键值大于 k,则进行切割和级联切割操作。
  2. 删除节点:删除节点的操作首先将节点 k 的键值减小到最低可能值(例如 -∞),然后执行提取最小值操作以移除该节点。
  3. 操作步骤:在执行减小键值和删除节点的操作时,涉及对斐波那契堆的调整,如切割、级联切割以及重新组织堆结构。示例中展示了将特定键值减小并相应调整堆结构的具体步骤。

斐波那契堆是一种基于树的数据结构,包括一系列具有最小堆或最大堆属性的树。在时间复杂度方面,它的操作比二项堆和二叉堆这些类似数据结构的操作更高效。

现在,我们将讨论其两个重要操作。

  1. 减小一个键值:将键的值减小到任意较低的值
  2. 删除一个节点:删除给定的节点

减小键值

在减小键值操作中,键的值会被减小到较低的值。

以下函数用于减小键值。

减小键值

  1. 选择要减小的节点 x,并将其值改为新值 k
  2. 如果 x 的父节点 y 不为空且父节点的键大于 k,则依次调用 Cut(x)Cascading-Cut(y)
  3. 如果 x 的键小于最小值的键,则将 x 标记为最小值。

切割

  1. x 从当前位置移除并添加到根列表中。
  2. 如果 x 被标记,则将其标记为 false。

级联切割

  1. 如果 y 的父节点不为空,则按照以下步骤操作。
  2. 如果 y 未被标记,则标记 y
  3. 否则,调用 Cut(y)Cascading-Cut(y 的父节点)

减小键值示例

以下示例可以帮助理解上述操作。

示例:将 46 减小到 15。

  1. 将值 46 减小到 15。 将 46 减小到 15

  2. 切割部分: 由于 24 ≠ null15 < 其父节点,将其切割并添加到根列表中。级联切割部分: 标记 24。 切割和级联切割部分

示例:将 35 减小到 5

  1. 将值 35 减小到 5。 将 35 减小到 5

  2. 切割部分:由于 26 ≠ null5 < 其父节点,将其切割并添加到根列表中。 切割 5 并添加到根列表中

  3. 级联切割部分:由于 26 已被标记,流程转向 CutCascading-CutCut(26):切割 26 并将其添加到根列表中,然后标记为 false。 切割 26 并添加到根列表中

Cascading-Cut(24): 由于 24 也被标记,再次调用 Cut(24)Cascading-Cut(7)。这些操作得到如下树结构。

切割 24 并添加到根列表中

  1. 由于 5 < 7,将 5 标记为最小值。 标记最小值

删除节点

这个过程使用了 减小键值提取最小值 操作。删除节点遵循以下步骤。

  1. k 是要被删除的节点。
  2. 应用减小键值操作,将 k 的值减小到最低可能值(即 -∞)。
  3. 应用提取最小值操作以移除该节点。

Python、Java 和 C/C++ 中的减小键值和删除节点操作

Python Java C C++

# Python 中的斐波那契堆

import math

class FibonacciTree:
def __init__(self, key):
self.key = key
self.children = []
self.order = 0

def add_at_end(self, t):
self.children.append(t)
self.order = self.order + 1


class FibonacciHeap:
def __init__(self):
self.trees = []
self.least = None
self.count = 0

def insert(self, key):
new_tree = FibonacciTree(key)
self.trees.append(new_tree)
if (self.least is None or key < self.least.key):
self.least = new_tree
self.count = self.count + 1

def get_min(self):
if self.least is None:
return None
return self.least.key

def extract_min(self):
smallest = self.least
if smallest is not None:
for child in smallest.children:
self.trees.append(child)
self.trees.remove(smallest)
if self.trees == []:
self.least = None
else:
self.least = self.trees[0]
self.consolidate()
self.count = self.count - 1
return smallest.key

def consolidate(self):
aux = (floor_log2(self.count) + 1) * [None]

while self.trees != []:
x = self.trees[0]
order = x.order
self.trees.remove(x)
while aux[order] is not None:
y = aux[order]
if x.key > y.key:
x, y = y, x
x.add_at_end(y)
aux[order] = None
order = order + 1
aux[order] = x

self.least = None
for k in aux:
if k is not None:
self.trees.append(k)
if (self.least is None
or k.key < self.least.key):
self.least = k


def floor_log2(x):
return math.frexp(x)[1] - 1


fheap = FibonacciHeap()

fheap.insert(11)
fheap.insert(10)
fheap.insert(39)
fheap.insert(26)
fheap.insert(24)

print('最小值:{}'.format(fheap.get_min()))

print('移除的最小值:{}'.format(fheap.extract_min()))
// Java 编程中对斐波那契堆的操作

class node {
node parent;
node left;
node right;
node child;
int degree;
boolean mark;
int key;

public node() {
this.degree = 0;
this.mark = false;
this.parent = null;
this.left = this;
this.right = this;
this.child = null;
this.key = Integer.MAX_VALUE;
}

node(int x) {
this();
this.key = x;
}

void set_parent(node x) {
this.parent = x;
}

node get_parent() {
return this.parent;
}

void set_left(node x) {
this.left = x;
}

node get_left() {
return this.left;
}

void set_right(node x) {
this.right = x;
}

node get_right() {
return this.right;
}

void set_child(node x) {
this.child = x;
}

node get_child() {
return this.child;
}

void set_degree(int x) {
this.degree = x;
}

int get_degree() {
return this.degree;
}

void set_mark(boolean m) {
this.mark = m;
}

boolean get_mark() {
return this.mark;
}

void set_key(int x) {
this.key = x;
}

int get_key() {
return this.key;
}
}

public class fibHeap {
node min;
int n;
boolean trace;
node found;

public boolean get_trace() {
return trace;
}

public void set_trace(boolean t) {
this.trace = t;
}

public static fibHeap create_heap() {
return new fibHeap();
}

fibHeap() {
min = null;
n = 0;
trace = false;
}

private void insert(node x) {
if (min == null) {
min = x;
x.set_left(min);
x.set_right(min);
} else {
x.set_right(min);
x.set_left(min.get_left());
min.get_left().set_right(x);
min.set_left(x);
if (x.get_key() < min.get_key())
min = x;
}
n += 1;
}

public void insert(int key) {
insert(new node(key));
}

public void display() {
display(min);
System.out.println();
}

private void display(node c) {
System.out.print("(");
if (c == null) {
System.out.print(")");
return;
} else {
node temp = c;
do {
System.out.print(temp.get_key());
node k = temp.get_child();
display(k);
System.out.print("->");
temp = temp.get_right();
} while (temp != c);
System.out.print(")");
}
}

public static void merge_heap(fibHeap H1, fibHeap H2, fibHeap H3) {
H3.min = H1.min;

if (H1.min != null && H2.min != null) {
node t1 = H1.min.get_left();
node t2 = H2.min.get_left();
H1.min.set_left(t2);
t1.set_right(H2.min);
H2.min.set_left(t1);
t2.set_right(H1.min);
}
if (H1.min == null || (H2.min != null && H2.min.get_key() < H1.min.get_key()))
H3.min = H2.min;
H3.n = H1.n + H2.n;
}

public int find_min() {
return this.min.get_key();
}

private void display_node(node z) {
System.out.println("right: " + ((z.get_right() == null) ? "-1" : z.get_right().get_key()));
System.out.println("left: " + ((z.get_left() == null) ? "-1" : z.get_left().get_key()));
System.out.println("child: " + ((z.get_child() == null) ? "-1" : z.get_child().get_key()));
System.out.println("degree " + z.get_degree());
}

public int extract_min() {
node z = this.min;
if (z != null) {
node c = z.get_child();
node k = c, p;
if (c != null) {
do {
p = c.get_right();
insert(c);
c.set_parent(null);
c = p;
} while (c != null && c != k);
}
z.get_left().set_right(z.get_right());


z.get_right().set_left(z.get_left());
z.set_child(null);
if (z == z.get_right())
this.min = null;
else {
this.min = z.get_right();
this.consolidate();
}
this.n -= 1;
return z.get_key();
}
return Integer.MAX_VALUE;
}

public void consolidate() {
double phi = (1 + Math.sqrt(5)) / 2;
int Dofn = (int) (Math.log(this.n) / Math.log(phi));
node[] A = new node[Dofn + 1];
for (int i = 0; i <= Dofn; ++i)
A[i] = null;
node w = min;
if (w != null) {
node check = min;
do {
node x = w;
int d = x.get_degree();
while (A[d] != null) {
node y = A[d];
if (x.get_key() > y.get_key()) {
node temp = x;
x = y;
y = temp;
w = x;
}
fib_heap_link(y, x);
check = x;
A[d] = null;
d += 1;
}
A[d] = x;
w = w.get_right();
} while (w != null && w != check);
this.min = null;
for (int i = 0; i <= Dofn; ++i) {
if (A[i] != null) {
insert(A[i]);
}
}
}
}

private void fib_heap_link(node y, node x) {
y.get_left().set_right(y.get_right());
y.get_right().set_left(y.get_left());

node p = x.get_child();
if (p == null) {
y.set_right(y);
y.set_left(y);
} else {
y.set_right(p);
y.set_left(p.get_left());
p.get_left().set_right(y);
p.set_left(y);
}
y.set_parent(x);
x.set_child(y);
x.set_degree(x.get_degree() + 1);
y.set_mark(false);
}

private void find(int key, node c) {
if (found != null || c == null)
return;
else {
node temp = c;
do {
if (key == temp.get_key())
found = temp;
else {
node k = temp.get_child();
find(key, k);
temp = temp.get_right();
}
} while (temp != c && found == null);
}
}

public node find(int k) {
found = null;
find(k, this.min);
return found;
}

public void decrease_key(int key, int nval) {
node x = find(key);
decrease_key(x, nval);
}

private void decrease_key(node x, int k) {
if (k > x.get_key())
return;
x.set_key(k);
node y = x.get_parent();
if (y != null && x.get_key() < y.get_key()) {
cut(x, y);
cascading_cut(y);
}
if (x.get_key() < min.get_key())
min = x;
}

private void cut(node x, node y) {
x.get_right().set_left(x.get_left());
x.get_left().set_right(x.get_right());

y.set_degree(y.get_degree() - 1);

x.set_right(null);
x.set_left(null);
insert(x);
x.set_parent(null);
x.set_mark(false);
}

private void cascading_cut(node y) {
node z = y.get_parent();
if (z != null) {
if (y.get_mark() == false)
y.set_mark(true);
else {
cut(y, z);
cascading_cut(z);
}
}
}

public void delete(node x) {
decrease_key(x, Integer.MIN_VALUE);
int p = extract_min();
}

public static void main(String[] args) {
fibHeap obj = create_heap();
obj.insert(7);
obj.insert(26);
obj.insert(30);
obj.insert(39);
obj.insert(10);
obj.display();

System.out.println(obj.extract_min());
obj.display();
System.out.println(obj.extract_min());
obj.display();
System.out.println(obj.extract_min());
obj.display();
System.out.println(obj.extract_min());
obj.display();
System.out.println(obj.extract_min());
obj.display();
}
}
// C 语言中的 Fibonacci 堆操作

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <math.h>

typedef struct _NODE
{
int key;
int degree;
struct _NODE *left_sibling;
struct _NODE *right_sibling;
struct _NODE *parent;
struct _NODE *child;
bool mark;
bool visited;
} NODE;

typedef struct fibanocci_heap
{
int n;
NODE *min;
int phi;
int degree;
} FIB_HEAP;

FIB_HEAP *make_fib_heap();
void insertion(FIB_HEAP *H, NODE *new, int val);
NODE *extract_min(FIB_HEAP *H);
void consolidate(FIB_HEAP *H);
void fib_heap_link(FIB_HEAP *H, NODE *y, NODE *x);
NODE *find_min_node(FIB_HEAP *H);
void decrease_key(FIB_HEAP *H, NODE *node, int key);
void cut(FIB_HEAP *H, NODE *node_to_be_decrease, NODE *parent_node);
void cascading_cut(FIB_HEAP *H, NODE *parent_node);
void Delete_Node(FIB_HEAP *H, int dec_key);

FIB_HEAP *make_fib_heap()
{
FIB_HEAP *H;
H = (FIB_HEAP *)malloc(sizeof(FIB_HEAP));
H->n = 0;
H->min = NULL;
H->phi = 0;
H->degree = 0;
return H;
}
void new_print_heap(NODE *n)
{
NODE *x;
for (x = n;; x = x->right_sibling)
{

if (x->child == NULL)
{
printf("node with no child (%d) \n", x->key);
}
else
{

printf("NODE(%d) with child (%d)\n", x->key, x->child->key);
new_print_heap(x->child);
}
if (x->right_sibling == n)
{
break;
}
}
}

void insertion(FIB_HEAP *H, NODE *new, int val)
{
new = (NODE *)malloc(sizeof(NODE));
new->key = val;
new->degree = 0;
new->mark = false;
new->parent = NULL;
new->child = NULL;
new->visited = false;
new->left_sibling = new;
new->right_sibling = new;
if (H->min == NULL)
{
H->min = new;
}
else
{
H->min->left_sibling->right_sibling = new;
new->right_sibling = H->min;
new->left_sibling = H->min->left_sibling;
H->min->left_sibling = new;
if (new->key < H->min->key)
{
H->min = new;
}
}
(H->n)++;
}

NODE *find_min_node(FIB_HEAP *H)
{
if (H == NULL)
{
printf(" \n Fibonacci 堆尚未创建 \n");
return NULL;
}
else
return H->min;
}

FIB_HEAP *unionHeap(FIB_HEAP *H1, FIB_HEAP *H2)
{
FIB_HEAP *Hnew;
Hnew = make_fib_heap();
Hnew->min = H1->min;

NODE *temp1, *temp2;
temp1 = Hnew->min->right_sibling;
temp2 = H2->min->left_sibling;

Hnew->min->right_sibling->left_sibling = H2->min->left_sibling;
Hnew->min->right_sibling = H2->min;
H2->min->left_sibling = Hnew->min;
temp2->right_sibling = temp1;

if ((H1->min == NULL) || (H2->min != NULL && H2->min->key < H1->min->key))
Hnew->min = H2->min;
Hnew->n = H1->n + H2->n;
return Hnew;
}

int cal_degree(int n)
{
int count = 0;
while (n > 0)
{
n = n / 2;
count++;
}
return count;
}
void consolidate(FIB_HEAP *H)
{
int degree, i, d;
degree = cal_degree(H->n);
NODE *A[degree], *x, *y, *z;
for (i = 0; i <= degree; i++)
{
A[i] = NULL;
}
x = H->min;
do
{
d = x->degree;


while (A[d] != NULL)
{
y = A[d];
if (x->key > y->key)
{
NODE *exchange_help;
exchange_help = x;
x = y;
y = exchange_help;
}
if (y == H->min)
H->min = x;
fib_heap_link(H, y, x);
if (y->right_sibling == x)
H->min = x;
A[d] = NULL;
d++;
}
A[d] = x;
x = x->right_sibling;
} while (x != H->min);

H->min = NULL;
for (i = 0; i < degree; i++)
{
if (A[i] != NULL)
{
A[i]->left_sibling = A[i];
A[i]->right_sibling = A[i];
if (H->min == NULL)
{
H->min = A[i];
}
else
{
H->min->left_sibling->right_sibling = A[i];
A[i]->right_sibling = H->min;
A[i]->left_sibling = H->min->left_sibling;
H->min->left_sibling = A[i];
if (A[i]->key < H->min->key)
{
H->min = A[i];
}
}
if (H->min == NULL)
{
H->min = A[i];
}
else if (A[i]->key < H->min->key)
{
H->min = A[i];
}
}
}
}

void fib_heap_link(FIB_HEAP *H, NODE *y, NODE *x)
{
y->right_sibling->left_sibling = y->left_sibling;
y->left_sibling->right_sibling = y->right_sibling;

if (x->right_sibling == x)
H->min = x;

y->left_sibling = y;
y->right_sibling = y;
y->parent = x;

if (x->child == NULL)
{
x->child = y;
}
y->right_sibling = x->child;
y->left_sibling = x->child->left_sibling;
x->child->left_sibling->right_sibling = y;
x->child->left_sibling = y;
if ((y->key) < (x->child->key))
x->child = y;

(x->degree)++;
}
NODE *extract_min(FIB_HEAP *H)
{

if (H->min == NULL)
printf("\n 堆为空");
else
{
NODE *temp = H->min;
NODE *pntr;
pntr = temp;
NODE *x = NULL;
if (temp->child != NULL)
{

x = temp->child;
do
{
pntr = x->right_sibling;
(H->min->left_sibling)->right_sibling = x;
x->right_sibling = H->min;
x->left_sibling = H->min->left_sibling;
H->min->left_sibling = x;
if (x->key < H->min->key)
H->min = x;
x->parent = NULL;
x = pntr;
} while (pntr != temp->child);
}

(temp->left_sibling)->right_sibling = temp->right_sibling;
(temp->right_sibling)->left_sibling = temp->left_sibling;
H->min = temp->right_sibling;

if (temp == temp->right_sibling && temp->child == NULL)
H->min = NULL;
else
{
H->min = temp->right_sibling;
consolidate(H);
}
H->n = H->n - 1;
return temp;
}
return H->min;
}

void cut(FIB_HEAP *H, NODE *node_to_be_decrease, NODE *parent_node)
{
NODE *temp_parent_check;

if (node_to_be_decrease == node_to_be_decrease->right_sibling)
parent_node->child = NULL;

node_to_be_decrease->left_sibling->right_sibling = node_to_be_decrease->right_sibling;
node_to_be_decrease->right_sibling->left_sibling = node_to_be_decrease->left_sibling;
if (node_to_be_decrease == parent_node->child)
parent_node->child = node_to_be_decrease->right_sibling;
(parent_node->degree)--;

node_to_be_decrease->left_sibling = node_to_be_decrease;
node_to_be_decrease->right_sibling = node_to_be_decrease;
H->min->left_sibling->right_sibling = node_to_be_decrease;
node_to_be_decrease->right_sibling = H->min;
node_to_be_decrease->left_sibling = H->min->left_sibling;
H->min->left_sibling = node_to_be_decrease;

node_to_be_decrease->parent = NULL;
node_to_be_decrease->mark = false;
}

void cascading_cut(FIB_HEAP *H, NODE *parent_node)
{
NODE *aux;
aux = parent_node->parent;
if (aux != NULL)
{
if (parent_node->mark == false)
{
parent_node->mark = true;
}
else
{
cut(H, parent_node, aux);
cascading_cut(H, aux);
}
}
}

void decrease_key(FIB_HEAP *H, NODE *node_to_be_decrease, int new_key)
{
NODE *parent_node;
if (H == NULL)
{
printf("\n FIbonacci heap not created ");
return;
}
if (node_to_be_decrease == NULL)
{
printf("Node is not in the heap");
}

else
{
if (node_to_be_decrease->key < new_key)
{
printf("\n Invalid new key for decrease key operation \n ");
}
else
{
node_to_be_decrease->key = new_key;
parent_node = node_to_be_decrease->parent;
if ((parent_node != NULL) && (node_to_be_decrease->key < parent_node->key))
{
printf("\n cut called");
cut(H, node_to_be_decrease, parent_node);
printf("\n cascading cut called");
cascading_cut(H, parent_node);
}
if (node_to_be_decrease->key < H->min->key)
{
H->min = node_to_be_decrease;
}
}
}
}

void *find_node(FIB_HEAP *H, NODE *n, int key, int new_key)
{
NODE *find_use = n;
NODE *f = NULL;
find_use->visited = true;
if (find_use->key == key)
{
find_use->visited = false;
f = find_use;
decrease_key(H, f, new_key);
}
if (find_use->child != NULL)
{
find_node(H, find_use->child, key, new_key);
}
if ((find_use->right_sibling->visited != true))
{
find_node(H, find_use->right_sibling, key, new_key);
}

find_use->visited = false;
}

FIB_HEAP *insertion_procedure()
{
FIB_HEAP *temp;
int no_of_nodes, ele, i;
NODE *new_node;
temp = (FIB_HEAP *)malloc(sizeof(FIB_HEAP));
temp = NULL;
if (temp == NULL)
{
temp = make_fib_heap();
}
printf(" \n enter number of nodes to be insert = ");
scanf("%d", &no_of_nodes);
for (i = 1; i <= no_of_nodes; i++)
{
printf("\n node %d and its key value = ", i);
scanf("%d", &ele);
insertion(temp, new_node, ele);
}
return temp;
}
void Delete_Node(FIB_HEAP *H, int dec_key)
{
NODE *p = NULL;
find_node(H, H->min, dec_key, -5000);
p = extract_min(H);
if (p != NULL)
printf("\n Node deleted");
else
printf("\n Node not deleted:some error");
}

int main(int argc, char **argv)
{
NODE *new_node, *min_node, *extracted_min, *node_to_be_decrease, *find_use;
FIB_HEAP *heap, *h1, *h2;
int operation_no, new_key, dec_key, ele, i, no_of_nodes;
heap = (FIB_HEAP *)malloc(sizeof(FIB_HEAP));
heap = NULL;
while (1)
{

printf(" \n choose below operations \n 1. Create Fibonacci heap \n 2. Insert nodes into fibonacci heap \n 3. Find min \n 4. Union \n 5. Extract min \n 6. Decrease key \n 7.Delete node \n 8. print heap \n 9. exit \n enter operation_no = ");
scanf("%d", &operation_no);

switch (operation_no)
{
case 1:
heap = make_fib_heap();
break;

case 2:
if (heap == NULL)
{
heap = make_fib_heap();
}
printf(" enter number of nodes to be insert = ");
scanf("%d", &no_of_nodes);
for (i = 1; i <= no_of_nodes; i++)
{
printf("\n node %d and its key value = ", i);
scanf("%d", &ele);
insertion(heap, new_node, ele);
}
break;

case 3:
min_node = find_min_node(heap);
if (min_node == NULL)
printf("No minimum value");
else
printf("\n min value = %d", min_node->key);
break;

case 4:
if (heap == NULL)
{
printf("\n no FIbonacci heap is created please create fibonacci heap \n ");
break;
}
h1 = insertion_procedure();
heap = unionHeap(heap, h1);
printf("Unified Heap:\n");
new_print_heap(heap->min);
break;

case 5:
if (heap == NULL)
printf("Fibonacci heap is empty");
else
{
extracted_min = extract_min(heap);
printf("\n min value = %d", extracted_min->key);
printf("\n Updated heap: \n");
new_print_heap(heap->min);
}
break;

case 6:
if (heap == NULL)
printf("Fibonacci heap is empty");
else
{
printf(" \n node to be decreased = ");
scanf("%d", &dec_key);
printf(" \n enter the new key = ");
scanf("%d", &new_key);
find_use = heap->min;
find_node(heap, find_use, dec_key, new_key);
printf("\n Key decreased- Corresponding heap:\n");
new_print_heap(heap->min);
}
break;
case 7:
if (heap == NULL)
printf("Fibonacci heap is empty");
else
{
printf(" \n Enter node key to be deleted = ");
scanf("%d", &dec_key);
Delete_Node(heap, dec_key);
printf("\n Node Deleted- Corresponding heap:\n");
new_print_heap(heap->min);
break;
}
case 8:
new_print_heap(heap->min);
break;

case 9:
free(new_node);
free(heap);
exit(0);

default:
printf("Invalid choice ");
}
}
}
// C++ 斐波那契堆的操作

#include <iostream>
#include <cmath>
#include <cstdlib>

using namespace std;

struct node
{
int n;
int degree;
node *parent;
node *child;
node *left;
node *right;
char mark;

char C;
};

class FibonacciHeap
{
private:
int nH;

node *H;

public:
node *InitializeHeap();
int Fibonnaci_link(node *, node *, node *);
node *Create_node(int);
node *Insert(node *, node *);
node *Union(node *, node *);
node *Extract_Min(node *);
int Consolidate(node *);
int Display(node *);
node *Find(node *, int);
int Decrease_key(node *, int, int);
int Delete_key(node *, int);
int Cut(node *, node *, node *);
int Cascase_cut(node *, node *);
FibonacciHeap() { H = InitializeHeap(); }
};

node *FibonacciHeap::InitializeHeap()
{
node *np;
np = NULL;
return np;
}

node *FibonacciHeap::Create_node(int value)
{
node *x = new node;
x->n = value;
return x;
}

node *FibonacciHeap::Insert(node *H, node *x)
{
x->degree = 0;
x->parent = NULL;
x->child = NULL;
x->left = x;
x->right = x;
x->mark = 'F';
x->C = 'N';
if (H != NULL)
{
(H->left)->right = x;
x->right = H;
x->left = H->left;
H->left = x;
if (x->n < H->n)
H = x;
}
else
{
H = x;
}
nH = nH + 1;
return H;
}

int FibonacciHeap::Fibonnaci_link(node *H1, node *y, node *z)
{
(y->left)->right = y->right;
(y->right)->left = y->left;
if (z->right == z)
H1 = z;
y->left = y;
y->right = y;
y->parent = z;

if (z->child == NULL)
z->child = y;

y->right = z->child;
y->left = (z->child)->left;
((z->child)->left)->right = y;
(z->child)->left = y;

if (y->n < (z->child)->n)
z->child = y;
z->degree++;
}

node *FibonacciHeap::Union(node *H1, node *H2)
{
node *np;
node *H = InitializeHeap();
H = H1;
(H->left)->right = H2;
(H2->left)->right = H;
np = H->left;
H->left = H2->left;
H2->left = np;
return H;
}

int FibonacciHeap::Display(node *H)
{
node *p = H;
if (p == NULL)
{
cout << "堆为空" << endl;
return 0;
}
cout << "堆的根节点为: " << endl;

do
{
cout << p->n;
p = p->right;
if (p != H)
{
cout << "-->";
}
} while (p != H && p->right != NULL);
cout << endl;
}

node *FibonacciHeap::Extract_Min(node *H1)
{
node *p;
node *ptr;
node *z = H1;
p = z;
ptr = z;
if (z == NULL)
return z;

node *x;
node *np;

x = NULL;

if (z->child != NULL)
x = z->child;

if (x != NULL)
{
ptr = x;
do
{
np = x->right;
(H1->left)->right = x;
x->right = H1;
x->left = H1->left;
H1->left = x;
if (x->n < H1->n)
H1 = x;

x->parent = NULL;
x = np;
} while (np != ptr);
}

(z->left)->right = z->right;
(z->right)->left = z->left;
H1 = z->right;

if (z == z->right && z->child == NULL)
H = NULL;

else
{
H1 = z->right;
Consolidate(H1);
}
nH = nH - 1;
return p;
}

int FibonacciHeap::Consolidate(node *H1)
{
int d, i;
float f = (log(nH)) / (log(2));
int D = f;
node *A[D];

for (i = 0; i <= D; i++)
A[i] = NULL;

node *x = H1;
node *y;
node *np;
node *pt = x;

do
{
pt = pt->right;

d = x->degree;

while (A[d] != NULL)

{
y = A[d];

if (x->n > y->n)

{
np = x;

x = y;

y = np;
}

if (y == H1)
H1 = x;
Fibonnaci_link(H1, y, x);
if (x->right == x)
H1 = x;
A[d] = NULL;
d = d + 1;
}

A[d] = x;
x = x->right;

}

while (x != H1);
H = NULL;
for (int j = 0; j <= D; j++)
{
if (A[j] != NULL)
{
A[j]->left = A[j];
A[j]->right = A[j];
if (H != NULL)
{
(H->left)->right = A[j];
A[j]->right = H;
A[j]->left = H->left;
H->left = A[j];
if (A[j]->n < H->n)
H = A[j];
}
else
{
H = A[j];
}
if (H == NULL)
H = A[j];
else if (A[j]->n < H->n)
H = A[j];
}
}
}

int FibonacciHeap::Decrease_key(node *H1, int x, int k)
{
node *y;
if (H1 == NULL)
{
cout << "堆为空" << endl;
return 0;
}
node *ptr = Find(H1, x);
if (ptr == NULL)
{
cout << "堆中未找到该节点" << endl;
return 1;
}

if (ptr->n < k)
{
cout << "输入的键值大于当前键值" << endl;
return 0;
}
ptr->n = k;
y = ptr->parent;
if (y != NULL && ptr->n < y->n)
{
Cut(H1, ptr, y);
Cascase_cut(H1, y);
}

if (ptr->n < H->n)
H = ptr;

return 0;
}

int FibonacciHeap::Cut(node *H1, node *x, node *y)

{
if (x == x->right)
y->child = NULL;
(x->left)->right = x->right;
(x->right)->left = x->left;
if (x == y->child)
y->child = x->right;
y->degree = y->degree - 1;
x->right = x;
x->left = x;
(H1->left)->right = x;
x->right = H1;
x->left = H1->left;
H1->left = x;
x->parent = NULL;
x->mark = 'F';
}

int FibonacciHeap::Cascase_cut(node *H1, node *y)
{
node *z = y->parent;
if (z != NULL)
{
if (y->mark == 'F')
{
y->mark = 'T';
}
else

{
Cut(H1, y, z);
Cascase_cut(H1, z);
}
}
}

node *FibonacciHeap::Find(node *H, int k)
{
node *x = H;
x->C = 'Y';
node *p = NULL;
if (x->n == k)
{
p = x;
x->C = 'N';
return p;
}

if (p == NULL)
{
if (x->child != NULL)
p = Find(x->child, k);
if ((x->right)->C != 'Y')
p = Find(x->right, k);
}

x->C = 'N';
return p;
}

int FibonacciHeap::Delete_key(node *H1, int k)
{
node *np = NULL;
int t;
t = Decrease_key(H1, k, -5000);
if (!t)
np = Extract_Min(H);
if (np != NULL)
cout << "Key Deleted" << endl;
else
cout << "Key not Deleted" << endl;
return 0;
}

int main()
{
int n, m, l;
FibonacciHeap fh;
node *p;
node *H;
H = fh.InitializeHeap();

p = fh.Create_node(7);
H = fh.Insert(H, p);
p = fh.Create_node(17);
H = fh.Insert(H, p);
p = fh.Create_node(26);
H = fh.Insert(H, p);
p = fh.Create_node(1);
H = fh.Insert(H, p);

fh.Display(H);

p = fh.Extract_Min(H);
if (p != NULL)
cout << "The node with minimum key: " << p->n << endl;
else
cout << "Heap is empty" << endl;

m = 26;
l = 16;
fh.Decrease_key(H, m, l);

m = 16;
fh.Delete_key(H, m);
}

复杂度

| 减小键值 | O(1) | | 删除节点 | O(log n) |