sort_heap

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Contents
  1. Definition
  2. Interface
  3. Description
  4. Return Value
  5. Complexity
  6. References
  7. See Also

Sorts the heap (it is no longer a heap after the call)

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Computing Stl Algorithms Heap

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Definition

The sort_heap() algorithm is defined in the standard header <algorithm> and in the nonstandard backward-compatibility header <algo.h>.

Interface

#include <algorithm>
template < class RandomAccessIterator >
   void sort_heap(
      RandomAccessIterator first, 
      RandomAccessIterator last
   );
template < class RandomAccessIterator, class Predicate >
   void sort_heap(
      RandomAccessIterator first, 
      RandomAccessIterator last,
      Predicate comp
   );

Parameters:

ParameterDescription
firstA random-access iterator addressing the position of the first element in the target heap
lastA random-access iterator addressing the position one past the final element in the target heap
compUser-defined predicate function object that defines sense in which one element is less than another. A binary predicate takes two arguments and returns true when satisfied and false when not satisfied

Description

Sort_heap function converts a heap into a sorted range (ascending order). It does the same thing than doing a http://codecogs.com/reference/computing/stl/algorithms/heap/pop_heap.php"pop_heap" on the heap until no more element is in the heap.

The first version compares objects using operator< and the second compares objects using a function object comp.

Return Value

None.

Complexity

Performs at most (last - first)*log(last - first) comparisons.

References

Example 1
Problem

This program illustrates the use of the STL sort_heap() algorithm (default version) to sort a (maximum) heap of integers into ascending order.

Workings
#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{ 
  int a[] = {100, 19, 36, 17, 3, 25, 1, 2, 7};
  vector<int> v(a, a+9);

  cout <<"\nHere are the values in the heap:\n";
  for (vector<int>::size_type i=0; i<v.size(); i++)
    cout <<v.at(i)<<" ";

  cout <<"\nNow we sort these values into ascending order.";
  sort_heap(v.begin(), v.end());

  cout <<"\nHere is the result:\n";
  for (vector<int>::size_type i=0; i<v.size(); i++)
    cout <<v.at(i)<<" ";
Solution

Output:

Here are the values in the heap:
100 19 36 17 3 25 1 2 7

Now we sort these values into ascending order.

Here is the result:
1 2 3 7 17 19 25 36 100

References

See Also