支持插入和抽取最小元素的斐波那契堆

Author: Dev-XYS

Fibonacci-Heap.cpp

@@ -0,0 +1,194 @@
+// Algorithm: Fibonacci Heap
+
+#include <cstdio>
+#include <cstring>
+#include <algorithm>
+
+#define NIL 0
+#define MAX_HEAP_SIZE 100010
+
+using namespace std;
+
+class FibonacciHeap
+{
+private:
+	struct node
+	{
+		node *child, *parent, *left, *right;
+		int key, degree;
+		bool mark;
+		node(int _key) : child(NIL), parent(NIL), left(NIL), right(NIL), key(_key), degree(0), mark(false) { }
+	};
+
+	node *min;
+	size_t heap_size;
+
+	void _M_insert_to(node *v, node *u);
+	void _M_insert_to_root_list(node *u);
+	void _M_remove_from_root_list(node *u);
+	void _M_link(node *v, node *u);
+	void _M_consolidate();
+	
+public:
+	FibonacciHeap();
+	void insert(int key);
+	int extract_min();
+};
+
+void FibonacciHeap::_M_insert_to(node *v, node *u)
+{
+	v->right = u->right;
+	v->left = u;
+	u->right->left = v;
+	u->right = v;
+}
+
+void FibonacciHeap::_M_insert_to_root_list(node *u)
+{
+	_M_insert_to(u, min);
+}
+
+void FibonacciHeap::_M_remove_from_root_list(node *u)
+{
+	u->left->right = u->right;
+	u->right->left = u->left;
+}
+
+void FibonacciHeap::_M_link(node *v, node *u)
+{
+	_M_remove_from_root_list(v);
+	if (u->child == NIL)
+	{
+		u->child = v;
+		v->parent = u;
+		v->left = v->right = v;
+	}
+	else
+	{
+		_M_insert_to(v, u->child);
+		v->parent = u;
+	}
+}
+
+void FibonacciHeap::_M_consolidate()
+{
+	static node *root_list[MAX_HEAP_SIZE];
+	node *first = min;
+	node *u = first;
+	int cnt = 0;
+	do
+	{
+		root_list[cnt++] = u;
+		u = u->right;
+	} while (u != first);
+	node *list[50];
+	memset(list, 0, sizeof(list));
+	for (int i = 0; i < cnt; i++)
+	{
+		node *x = root_list[i];
+		while (list[x->degree] != NIL)
+		{
+			node *y = list[x->degree];
+			if (x->key > y->key) swap(x, y);
+			_M_link(y, x);
+			list[x->degree++] = NIL;
+		}
+		list[x->degree] = x;
+	}
+	min = NIL;
+	for (int i = 0; i < 50; i++)
+	{
+		if (list[i] != NIL)
+		{
+			if (min == NIL)
+			{
+				min = list[i];
+				list[i]->left = list[i]->right = list[i];
+			}
+			else
+			{
+				_M_insert_to_root_list(list[i]);
+				if (list[i]->key < min->key) min = list[i];
+			}
+		}
+	}
+}
+
+FibonacciHeap::FibonacciHeap() : min(NIL), heap_size(0) { }
+
+void FibonacciHeap::insert(int key)
+{
+	if (min == NIL)
+	{
+		min = new node(key);
+		min->left = min->right = min;
+	}
+	else
+	{
+		node *u = new node(key);
+		_M_insert_to_root_list(u);
+		if (key < min->key) min = u;
+	}
+	heap_size++;
+}
+
+int FibonacciHeap::extract_min()
+{
+	int res = min->key;
+	if (min != NIL)
+	{
+		if (heap_size == 1)
+		{
+			min = NIL;
+		}
+		else
+		{
+			if (min->child != NIL)
+			{
+				static node *child_list[MAX_HEAP_SIZE];
+				node *first = min->child;
+				node *u = first;
+				int cnt = 0;
+				do
+				{
+					child_list[cnt++] = u;
+					u = u->right;
+				} while (u != first);
+				for (int i = 0; i < cnt; i++)
+				{
+					_M_insert_to_root_list(child_list[i]);
+				}
+			}
+			_M_remove_from_root_list(min);
+			min = min->right;
+			_M_consolidate();
+		}
+	}
+	heap_size--;
+	return res;
+}
+
+int main()
+{
+	FibonacciHeap H;
+	char op[10];
+	int x;
+	while (true)
+	{
+		scanf("%s", op);
+		if (strcmp(op, "push") == 0)
+		{
+			scanf("%d", &x);
+			H.insert(x);
+		}
+		else if (strcmp(op, "pop") == 0)
+		{
+			printf("%d\n", H.extract_min());
+		}
+		else
+		{
+			printf("Command not found.\n");
+		}
+	}
+	return 0;
+}