C++ program to find largest list of prime numbers

Algorithm:

prime_List(N)
    1.  if(N%2)==0
    2.  Express it as summation of (N/2) number of 2
    3.  Else if(N%2)!=0
        //So that N can be even, for example N=19, so now N=19-3=16
    4.  Set N=N-3   
    5.  Print (N/2) numbers of 2
    6.  Print 3
    7.  END of Program.

C++ program

#include<bits/stdc++.h>
using namespace std;

int list_prime(int n)
{	
	int i;
	if(n<2)
	{
		cout<<"Summation not possible\n";
	}
	//if n can be divided by 2, then we can express 
	//it as summation of 2 only
	else if(n%2==0)			
	{
		for(i=1;i<=n/2;i++)
		{
			cout<<2<<" ";
		}
	}
	else
	{
		//making the number even
		n=n-3;
		//n can be divided by 2 now
		for(i=1;i<=n/2;i++)	
			cout<<2<<" ";
		//add 3, and the summation will be now n
		cout<<3<<" ";
	}
}

int main()
{
	int i,n;
	
	cin>>n;
	
	list_prime(n);

	return 0;
}

Output

7
2 2 3