i want to make a programm to find all the combinations of n numbers choosing the k of them
for example
[1 2 3 4 5]
the combinations of two of them are
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
the combinations of 3 numbers of them are
1 2 3
1 2 4
1 2 5
1 3 4
1 3 5
1 4 5
2 3 4
2 3 5
2 4 5
3 4 5
i have made this programm that it is close to find the write solution but i cannot go farther
please i want help..
if you can improve my programm or suggest me something already done..
Code:
#include"stdafx.h"
#include"iostream"
#include<vector>
usingnamespace std;
vector<vector<int>> v;
int arithmos_comb_sinolikos;
void comb(vector<int> A,int k,vector<vector<int>> &v,int column_v,int row);
int arithmos_comb_epomeno(int n,int k);
int factorial(int number) ;
ostream & print(const vector<int> & v);
ostream & print(const vector<vector<int> > & v);
int _tmain(int argc, _TCHAR* argv[])
{
int arr[]={1,4,6,7,9};
//cout<<arr[0];
vector<int> A(arr,arr+5);
v.push_back(vector<int>());
//cout<<v.size();
//cout<<A[3];
arithmos_comb_sinolikos=arithmos_comb_epomeno(A.size(),2);
//cout<<arithmos_comb_epomeno(4,2);
//cout<<arithmos_comb_sinolikos;
comb(A,2,v,0,0);
//print(v);
cin>>arr[0];
}
void comb(vector<int> A,int k,vector<vector<int>> &v,int column_v,int row)
{
if(row>=arithmos_comb_sinolikos)
{
//cout<<"epistrefei_giati_row>=arithmos_comb"<<endl;
//return;
}
else
{
}
cout<<endl<<endl<<"mpike_sto_comb";
print(v);
for(int i=column_v;i<=A.size()-k+column_v;i++)
{
cout<<"mpike_sto_proto_for i="<<i<<endl;
for(int y=0;y<arithmos_comb_epomeno(A.size()-column_v-i-1,k-column_v-1);y++)
{
cout<<"mpike_sto_deytero_for y="<<y<<endl;
v[v.size()-1].push_back(A[i]);
print(v);
cout<<"edaxei"<<endl;
cout<<"column_v="<<column_v<<endl;
if(column_v+1<k)
{
cout<<"mpike_sto_mikrotero_k"<<endl;
comb(A,k,v,column_v+1,row);
//return;
}
else
{
cout<<"mpike_sto_megalitero_k"<<endl;
//v[v.size()-1].push_back(A[i+column_v]);
v.push_back(vector<int> ());
column_v=0;
return;
//comb(A,k,v,0,stili_A,row+1);
//return;
}
}
}
}
int arithmos_comb_epomeno(int n,int k)
{
return (factorial(n)/(factorial(k)*factorial(n-k)));
}
int factorial(int number) {
int temp;
if(number <= 1) return 1;
temp = number * factorial(number - 1);
return temp;
}
ostream & print(const vector<int> & v)
{
for (int i=0; i<v.size(); i++)
cout << v[i] << ' ';
return cout;
}
ostream & print(const vector<vector<int> > & v)
{
for (int i=0; i<v.size(); i++)
{
for (int j=0; j<v[i].size(); j++)
cout << v[i][j] << ' ';
cout << endl;
}
return cout;
}
