How to show combinations of strings

[MKAIF]

I wanted to show all possible combinations of size 2, size 3 to size N
For example there are 4 words (string):

one 
two 
three 
four

combinations are possible:

one two 
one three 
one four 
two three 
two four 
three four 
one two three 
one two four 
one three four 
two three four 
one two three four

So we have N = 4 and the number of combinations = 11. It is not interested in forming a combination with 1 word (one, two, three and four).

Here's a solution:

#include <stdio.h>
#define N 5
void display(int state[], char *t[])
{
  int i;
  for (i = 0; i < N; i++)
    if (state[i])
      printf("%s ", t[i]);
  puts("" );
}
void part(int h, int state[], char *t[])
{
  enum { ABSENT, PRESENT };
  if (h < 0)
    display(state, t);
  else
    {
      state[h] = ABSENT;
      part(h - 1, state, t);
      state[h] = PRESENT;
      part(h - 1, state, t);
    }
}
int main(void)
{
  char *t[N] = { "name", "surname", "age", "address", "employment" };
  int state[N];
  part(N - 1, state, t);
  return 0;
}

it displays:

name
surname
name surname
age
name age
surname age
name surname age
address
name address
surname address
name surname address
age address
name age address
surname age address
name surname age address
employment
name employment
surname employment
name surname employment
age employment
name age employment
surname age employment
name surname age employment
address employment
name address employment
surname address employment
name surname address employment
age address employment
name age address employment
surname age address employment
name surname age address employment

How to modify the solution to get the combinations from size 2 and is also sorted (size 2 then 3 then 4 and 5)?

The desired result is obtained:

name surname
name age
name address
name employment
surname age
surname address
surname employment
age address
age employment
address employment
name surname age
name surname address
name surname employment
name age address
name age employment
name address employment
surname age address
surname age employment
surname address employment
age address employment
name surname age address
name surname age employment
name surname address employment
name age address employment
surname age address employment
name surname age address employment

Can you help me?

[Zecho]

I found a solution that allows this, which is also based on a status table. But I made a function

displayAllPossibilites void (char * t [N], unsigned nbAff)

I call in the main

for (i=2;i<=N;i++)
       displayAllPossibilites(t,i);

This function displays all the possible combinations of nbAff words. So the display is sorted.

It makes the state the first word to 1 and then calls a recursive function that takes care to all possibilities with the words that remain. Then it passes the 2nd word and so on.

I do not know if I am clear, but I hope to have you at least have a track.

[MKAIF]

Please can you give me details of your solution yet because I do not understand? It is possible to understand the solution better because I need to post the rest of my work?

[Zecho]

No I cannot give the solution because this is not the custom here. I suppose you store your results and want to sort. It is a solution, especially if you have to reuse your results later. My solution is simply to show that if you want you can always store rather than display. But in this case, perhaps a sort is more efficient, I have not compared.

[CitricAcid]

If I were you, I will use the method of binary masks to validate/inhibit value and access the following. A simple table you can then return the names of values that match. For example: pseudo C code:

enum
{    name              1<<0;
     surname         1<<1;
     address        1<<2;
}

You can then use the operators corresponding bits to express the full results. If you have the doc on the C: |, &, ^ and ~.

I have not much time to explain more if you feel comfortable with these operators, I think it can go fast enough.

[Zecho]

It is an idea that he should dig, even if nothing comes to my mind like that, there might be ways to do something.

The problem is if N = 256815, you will never have enough bits. Mine solution works, even if it probably would dynamically create tables, rather than return N words in hand with the statement.

Well OK, human civilization will disappear until all possibilities are displayed but that is not the issue ....