# ins_sort(3C++)

**ins_sort --
sort an array using an insertion sort algorithm
**

## Synopsis

template <class **T**>
void ins_sort(**T*** b,**T*** e);
template <class **T**>
void ins_sort_r(int (*rel)(const **T***,const **T***),
**T*** b,**T*** e);

## Assumptions

(1) For the plain version, **T****::operator<**
defines a total ordering relation on **T**.

(2) For the relational version, **rel** defines a total ordering
relation on **T**.

(3) **T** has **operator=**.

## Description

These functions stably sort an array in place using an insertion sort algorithm.

template <class T>
void ins_sort(T* b,T* e);

Uses **T::operator<** to define the ordering relation
used by the sorting algorithm.

template <class **T**>
void ins_sort_r(int (*rel)(const **T***,const **T***),**T*** b,**T*** e);

Uses **rel** to define the ordering relation used by the
sorting algorithm.

## Complexity

If *N* is the size of the array, then complexity
is *O(N*N)*.
On average, *N*N/4*
tests of the ordering relation and *N*N/4* assignments
are done.

## Notes

Insertion sorting is the algorithm of choice when either: 1) the size of the
array is small; OR 2) the number of elements out of order is small;
OR 3) the average
distance between the original position of an element and its final destination
is small.
(By "small" we mean less than 16.)

Because a Block (see **Block(3C++)**) can always be used wherever
an array is called for, Array Algorithms can also be used with Blocks. In fact,
these two components were actually designed to be used together.

## References

**Array_alg**(3C++),
**merge_sort**(3C++),
**sort**(3C++),
**Block**(3C++)

*
© 2004 The SCO Group, Inc. All rights reserved.
*

UnixWare 7 Release 7.1.4 - 25 April 2004