C++/STL Algorithms Merge/inplace merge
Generic merge algorithms: Merge the two sorted halves of vector3 in place to obtain a sorted vector3
#include <iostream>
#include <cassert>
#include <algorithm>
#include <vector>
using namespace std;
int main()
{
vector<int> vector1(5);
vector<int> vector2(5);
vector<int> vector3(10);
for (int i = 0; i < 5; ++i)
vector1[i] = 2 * i;
for (int i = 0; i < 5; ++i)
vector2[i] = 1 + 2 * i;
merge(vector1.begin(), vector1.end(), vector2.begin(), vector2.end(), vector3.begin());
inplace_merge(vector3.begin(), vector3.begin() + 5,vector3.end());
for (int i = 0; i < 10; ++i)
cout << vector3[i];
return 0;
}
/*
0123456789
*/
inplace_merge a list
/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
#include <iostream>
#include <vector>
#include <deque>
#include <list>
#include <set>
#include <map>
#include <string>
#include <algorithm>
#include <iterator>
#include <functional>
#include <numeric>
/* PRINT_ELEMENTS()
* - prints optional C-string optcstr followed by
* - all elements of the collection coll
* - separated by spaces
*/
template <class T>
inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="")
{
typename T::const_iterator pos;
std::cout << optcstr;
for (pos=coll.begin(); pos!=coll.end(); ++pos) {
std::cout << *pos << " ";
}
std::cout << std::endl;
}
/* INSERT_ELEMENTS (collection, first, last)
* - fill values from first to last into the collection
* - NOTE: NO half-open range
*/
template <class T>
inline void INSERT_ELEMENTS (T& coll, int first, int last)
{
for (int i=first; i<=last; ++i) {
coll.insert(coll.end(),i);
}
}
using namespace std;
int main()
{
list<int> coll;
// insert two sorted sequences
INSERT_ELEMENTS(coll,1,7);
INSERT_ELEMENTS(coll,1,8);
PRINT_ELEMENTS(coll);
// find beginning of second part (element after 7)
list<int>::iterator pos;
pos = find (coll.begin(), coll.end(), // range
7); // value
++pos;
// merge into one sorted range
inplace_merge (coll.begin(), pos, coll.end());
PRINT_ELEMENTS(coll);
}
/*
1 2 3 4 5 6 7 1 2 3 4 5 6 7 8
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8
*/
std::inplace_merge
#include <iostream>
using std::cout;
using std::endl;
#include <algorithm>
#include <vector>
#include <iterator>
int main()
{
const int SIZE = 10;
int a1[ SIZE ] = { 1, 3, 5, 7, 9, 1, 3, 5, 7, 9 };
std::vector< int > v1( a1, a1 + SIZE ); // copy of a
std::ostream_iterator< int > output( cout, " " );
cout << "Vector v1 contains: ";
std::copy( v1.begin(), v1.end(), output );
std::inplace_merge( v1.begin(), v1.begin() + 2, v1.end() );
cout << "\nAfter inplace_merge, v1 contains: ";
std::copy( v1.begin(), v1.end(), output );
return 0;
}
/*
Vector v1 contains: 1 3 5 7 9 1 3 5 7 9
After inplace_merge, v1 contains: 1 3 5 7 9 1 3 5 7 9
*/