ossrv_pub/boost_apis/boost/pending/fibonacci_heap.hpp
changeset 0 e4d67989cc36
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ossrv_pub/boost_apis/boost/pending/fibonacci_heap.hpp	Tue Feb 02 02:01:42 2010 +0200
@@ -0,0 +1,268 @@
+// (C) Copyright Jeremy Siek    2004.
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+#ifndef BOOST_FIBONACCI_HEAP_HPP
+#define BOOST_FIBONACCI_HEAP_HPP
+
+#if defined(__sgi) && !defined(__GNUC__)
+# include <math.h>
+#else
+# include <cmath>
+#endif
+#include <iosfwd>
+#include <vector>
+#include <functional>
+#include <boost/config.hpp>
+#include <boost/property_map.hpp>
+
+//
+// An adaptation of Knuth's Fibonacci heap implementation
+// in "The Stanford Graph Base", pages 475-482.
+//
+
+namespace boost {
+
+
+template <class T, 
+          class Compare = std::less<T>,
+          class ID = identity_property_map>
+class fibonacci_heap
+{
+  typedef typename boost::property_traits<ID>::value_type size_type;
+  typedef T value_type;
+protected:
+  typedef fibonacci_heap self;
+  typedef std::vector<size_type> LinkVec;
+  typedef typename LinkVec::iterator LinkIter;
+public:
+
+  fibonacci_heap(size_type n, 
+                 const Compare& cmp, 
+                 const ID& id = identity_property_map())
+    : _key(n), _left(n), _right(n), _p(n), _mark(n), _degree(n),
+      _n(0), _root(n), _id(id), _compare(cmp), _child(n),
+#if defined(BOOST_MSVC) || defined(__ICL) // need a new macro?
+      new_roots(size_type(log(float(n))) + 5) { }
+#else
+      new_roots(size_type(std::log(float(n))) + 5) { }
+#endif
+
+  // 33
+  void push(const T& d) {
+    ++_n;
+    size_type v = get(_id, d);
+    _key[v] = d;
+    _p[v] = nil();
+    _degree[v] = 0;
+    _mark[v] = false;
+    _child[v] = nil();
+    if (_root == nil()) {
+      _root = _left[v] = _right[v] = v;
+      //std::cout << "root added" << std::endl;
+    } else {
+      size_type u = _left[_root];
+      _left[v] = u;
+      _right[v] = _root;
+      _left[_root] = _right[u] = v;
+      if (_compare(d, _key[_root]))
+        _root = v;
+      //std::cout << "non-root node added" << std::endl;
+    }
+  }
+  T& top() { return _key[_root]; }
+  const T& top() const { return _key[_root]; }
+
+  // 38
+  void pop() {
+    --_n;
+    int h = -1;
+    size_type v, w;
+    if (_root != nil()) {
+      if (_degree[_root] == 0) {
+        v = _right[_root];
+      } else {
+        w = _child[_root];
+        v = _right[w];
+        _right[w] = _right[_root];
+        for (w = v; w != _right[_root]; w = _right[w])
+          _p[w] = nil();
+      }
+      while (v != _root) {
+        w = _right[v];
+        add_tree_to_new_roots(v, new_roots.begin(), h);
+        v = w;
+      }
+      rebuild_root_list(new_roots.begin(), h);
+    }
+  }
+  // 39
+  inline void add_tree_to_new_roots(size_type v, 
+                                    LinkIter new_roots,
+                                    int& h)
+  {
+    int r;
+    size_type u;
+    r = _degree[v];
+    while (1) {
+      if (h < r) {
+        do { 
+          ++h; 
+          new_roots[h] = (h == r ? v : nil());
+        } while (h < r);
+        break;
+      }
+      if (new_roots[r] == nil()) {
+        new_roots[r] = v;
+        break;
+      }
+      u = new_roots[r];
+      new_roots[r] = nil();
+      if (_compare(_key[u], _key[v])) {
+        _degree[v] = r;
+        std::swap(u, v);
+      }
+      make_child(u, v, r);
+      ++r;
+    }
+    _degree[v] = r;
+  }
+  // 40
+  void make_child(size_type u, size_type v, size_type r) {
+    if (r == 0) {
+      _child[v] = u;
+      _left[u] = u;
+      _right[u] = u;
+    } else {
+      size_type t = _child[v];
+      _right[u] = _right[t];
+      _left[u] = t;
+      _right[t] = u;
+      _left[_right[u]] = u;
+    }
+    _p[u] = v;
+  }
+  // 41
+  inline void rebuild_root_list(LinkIter new_roots, int& h)
+  {
+    size_type u, v, w;
+    if (h < 0)
+      _root = nil();
+    else {
+      T d;
+      u = v = new_roots[h];
+      d = _key[u];
+      _root = u;
+      for (h--; h >= 0; --h)
+        if (new_roots[h] != nil()) {
+          w = new_roots[h];
+          _left[w] = v;
+          _right[v] = w;
+          if (_compare(_key[w], d)) {
+            _root = w;
+            d = _key[w];
+          }
+          v = w;
+        }
+      _right[v] = u;
+      _left[u] = v;
+    }
+  }
+
+  // 34
+  void update(const T& d) {
+    size_type v = get(_id, d);
+    assert(!_compare(_key[v], d));
+    _key[v] = d;
+    size_type p = _p[v];
+    if (p == nil()) {
+      if (_compare(d, _key[_root]))
+        _root = v;
+    } else if (_compare(d, _key[_root]))
+      while (1) {
+        size_type r = _degree[p];
+        if (r >= 2)
+          remove_from_family(v, p);
+        insert_into_forest(v, d);
+        size_type pp = _p[p];
+        if (pp == nil()) {
+          --_degree[p];
+          break;
+        }
+        if (_mark[p] == false) {
+          _mark[p] = true;
+          break;
+        } else
+          --_degree[p];
+        v = p;
+        p = pp;
+      }
+  }
+
+  inline size_type size() const { return _n; }
+  inline bool empty() const { return _n == 0; }
+
+  void print(std::ostream& os) {
+    if (_root != nil()) {
+      size_type i = _root;
+      do {
+        print_recur(i, os);
+        os << std::endl;
+        i = _right[i];
+      } while (i != _root);
+    }
+  }
+
+protected:
+  // 35
+  inline void remove_from_family(size_type v, size_type p) {
+    size_type u = _left[v];
+    size_type w = _right[v];
+    _right[u] = w;
+    _left[w] = u;
+    if (_child[p] == v)
+      _child[p] = w;
+  }
+  // 36
+  inline void insert_into_forest(size_type v, const T& d) {
+    _p[v] = nil();
+    size_type u = _left[_root];
+    _left[v] = u;
+    _right[v] = _root;
+    _left[_root] = _right[u] = v;
+    if (_compare(d, _key[_root]))
+      _root = v;
+  }
+
+  void print_recur(size_type x, std::ostream& os) {
+    if (x != nil()) {
+      os << x;
+      if (_child[x] != nil()) {
+        os << "(";
+        size_type i = _child[x];
+        do {
+          print_recur(i, os); os << " ";
+          i = _right[i];
+        } while (i != _child[x]);
+        os << ")";
+      }
+    }
+  }
+  
+  size_type nil() const { return _left.size(); }
+
+  std::vector<T> _key;
+  LinkVec _left, _right, _p;
+  std::vector<bool> _mark;
+  LinkVec _degree;
+  size_type _n, _root;
+  ID _id;
+  Compare _compare;
+  LinkVec _child;
+  LinkVec new_roots;
+};
+
+} // namespace boost
+
+
+#endif // BOOST_FIBONACCI_HEAP_HPP