Sorting Algorithm of STL

 

Sorting

Sort	Sort elements in range (function template)
Stable_sort	Sort elements preserving order of equivalents (function template)
Partial_sort	Partially sort elements in range (function template)
Partial_sort_copy	Copy and partially sort range (function template)
Nth_element	Sort element in range (function template)

 

Among them, sort, and stable_sort have appeared in many of my blogs and are no longer cumbersome here. If you want to review sort and stable_sort, you can refer to my blog

1partial_sort

template <class RandomAccessIterator>  void partial_sort ( RandomAccessIterator first, RandomAccessIterator middle,                      RandomAccessIterator last );template <class RandomAccessIterator, class Compare>  void partial_sort ( RandomAccessIterator first, RandomAccessIterator middle,                      RandomAccessIterator last, Compare comp );

The above is the prototype of its function, which is based on the intermediate address you give, and then partially sorted, for example, the address you give is v. begin (), V. begin () + 5, V. end (), where the value of V is 10, then the result is sorted by the first five, and the last five are sorted by the original order.

 

#include<iostream>#include<string>#include<vector>#include<algorithm>#include<functional>using namespace std;int main(){int a[]={10,9,8,7,6,5,4,3,2,1};vector<int>v(a,a+10);partial_sort(v.begin(),v.begin()+5,v.end());for(vector<int>::iterator itera=v.begin();itera!=v.end();++itera){cout<<*itera<<" ";}cout<<endl;system("pause");return 0;}

#include<iostream>#include<string>#include<vector>#include<algorithm>#include<functional>using namespace std;bool isBigger(int a,int b){return a>b;}int main(){int a[]={1,2,3,4,5,6,7,8,9,10};vector<int>v(a,a+10);partial_sort(v.begin(),v.begin()+5,v.end(),isBigger);for(vector<int>::iterator itera=v.begin();itera!=v.end();++itera){cout<<*itera<<" ";}cout<<endl;system("pause");return 0;}

The code is simple. You don't have to explain it.

2partial_sort_copy,

The function prototype is as follows:

template <class InputIterator, class RandomAccessIterator>  RandomAccessIterator    partial_sort_copy ( InputIterator first,InputIterator last,                        RandomAccessIterator result_first,                        RandomAccessIterator result_last );template <class InputIterator, class RandomAccessIterator, class Compare>  RandomAccessIterator    partial_sort_copy ( InputIterator first,InputIterator last,                        RandomAccessIterator result_first,                        RandomAccessIterator result_last, Compare comp );

In fact, it is equivalent to the combination of sort () and copy. The so-called partial does not have a given range. In fact, it uses a lot of data, or begin ---> end

Check the Code:

#include<iostream>#include<string>#include<algorithm>#include<functional>#include<vector>using namespace std;int main(){int a[]={4,5,2,1,3,6,9,8,7,2};vector<int>v(a,a+10);vector<int>vv(10);partial_sort_copy(v.begin(),v.end(),vv.begin(),vv.end());for(vector<int>::iterator itera=vv.begin(); itera!=vv.end();++itera){cout<<*itera<<" ";}cout<<endl;system("pause");return 0;}

#include<iostream>#include<string>#include<algorithm>#include<functional>#include<vector>using namespace std;bool isBigger(int a,int b){return a>b;}int main(){int a[]={4,5,2,1,3,6,9,8,7,2};vector<int>v(a,a+10);vector<int>vv(10);partial_sort_copy(v.begin(),v.end(),vv.begin(),vv.end(),isBigger);for(vector<int>::iterator itera=vv.begin(); itera!=vv.end();++itera){cout<<*itera<<" ";}cout<<endl;system("pause");return 0;}

Use of the nth_element () method in STL by calling nth_element (start,
The START + N, end) method can place the nth element at the nth position (starting from 0, where the subscript is N ), in addition, elements smaller than this element are placed before this element. Elements larger than this element are placed behind this element, but they cannot be ordered.

The function prototype is as follows:

template <class RandomAccessIterator>  void nth_element ( RandomAccessIterator first, RandomAccessIterator nth,                     RandomAccessIterator last );template <class RandomAccessIterator, class Compare>  void nth_element ( RandomAccessIterator first, RandomAccessIterator nth,                     RandomAccessIterator last, Compare comp );

Check the Code:

#include<iostream>#include<string>#include<vector>#include<algorithm>#include<functional>using namespace std;int main(){int a[]={10,4,2,7,6,5,9,3,8,1};vector<int>v(a,a+10);for(vector<int>::iterator itera=v.begin();itera!=v.end();++itera){cout<<*itera<<" ";}cout<<endl;nth_element(v.begin(),v.begin()+6,v.end());for(vector<int>::iterator iterb=v.begin();iterb!=v.end();++iterb){cout<<*iterb<<" ";}cout<<endl;system("pause");return 0;}