sort set c++ code example

Example 1: c++ sort

int arr[]= {2,3,5,6,1,2,3,6,10,100,200,0,-10};
    int n = sizeof(arr)/sizeof(int);  
    sort(arr,arr+n);

    for(int i: arr)
    {
        cout << i << " ";
    }

Example 2: array sort c++

#include <iostream>
2 #include <array>
3 #include <string>
4 #include <algorithm>
5
6 using namespace std;
7
8 int main(){
9 array<string, 4> colours = {"blue", "black", "red", "green"};
10 for (string colour : colours){
11 cout << colour << ' ';
12 }
13 cout << endl;
14 sort(colours.begin(), colours.end());
15 for (string colour : colours){
16 cout << colour << ' ';
17 }
18 return 0;
19 }
66
20
21 /*
22 Output:
23 blue black red green
24 black blue green red
25 */

Example 3: c++ set sort order

struct cmpStruct {
  bool operator() (int const & lhs, int const & rhs) const
  {
    return lhs > rhs;
  }
};

std::set<int, cmpStruct > myInverseSortedSet;

Example 4: merge sort c++

#include "tools.hpp"
/*   >>>>>>>> (Recursive function that sorts a sequence of) <<<<<<<<<<<< 
     >>>>>>>> (numbers in ascending order using the merge function) <<<<                                 */
std::vector<int> sort(size_t start, size_t length, const std::vector<int>& vec)
{
	if(vec.size()==0 ||vec.size() == 1)
	return vec;

	vector<int> left,right; //===>  creating left and right vectors 

	size_t mid_point = vec.size()/2; //===>   midle point between the left vector and the right vector 

	for(int i = 0 ; i < mid_point; ++i){left.emplace_back(vec[i]);} //===>  left vector 
	for(int j = mid_point; j < length; ++j){ right.emplace_back(vec[j]);} //===>  right vector 

	left = sort(start,mid_point,left); //===>  sorting the left vector 
	right = sort(mid_point,length-mid_point,right);//===>  sorting the right vector 
	

	return merge(left,right); //===>   all the function merge to merge between the left and the right
}
/*

>>>>> (function that merges two sorted vectors of numberss) <<<<<<<<<                                    */ 
vector<int> merge(const vector<int>& a, const vector<int>& b)
{
	vector<int> merged_a_b(a.size()+b.size(),0); // temp vector that includes both left and right vectors
	int i = 0;
	int j = 0;
	int k = 0;
	int left_size = a.size();
	int right_size = b.size();
	while(i<left_size && j<right_size) 
	{
		if(a[i]<b[j])
		{
			merged_a_b[k]=a[i];
			i++;
		}
		else
		{
			merged_a_b[k]=b[j];
			j++;
		}
		k++;
	}
	while(i<left_size)
	{
		merged_a_b[k]=a[i];
		i++;
		k++;
	}
	while(j<right_size)
	{
		merged_a_b[k]=b[j];
		j++;
		k++;
	}
	
	return merged_a_b;

}