Printable View
Do u have any idea to list out all the combination of several set.
For example:
set A={a,b,c}
set B={e,f}
set C= {g,h,i}
All the combination would be:
aeg,aeh,aei,afg,afh,afi,beg,beh,bei,bfg,bfh,bfi,veg,ceh,cei,cfg,cfh,cfi
what is the algorithm to generate all the combination? Thank you very much.
I am using C programming.
Something like:
should work, depending on what the sets are exactly.Code:for (int i = 0 ; i < #of-items-in-A ; ++i) {
for (int j = 0 ; j < #of-items-in-B ; ++j) {
for (int k = 0 ; k < #of-items-in-C ; ++k) {
printf("Combination: {%s,%s,%s}", A[i], B[j], C[k]);
}
}
}
can i have a general algorithm so that the user is able to choose how many set?
No, we aren't going to write your code for you. Do it yourself.
The trick is to use recursion.
Say you have n arrays A of items, numbered 0 to n-1.
Now you write a function 'combinations(i)' that generates all combinations of the arrays i to n-1.
Clearly, if i == n, you are done, from zero sets you can pick exactly one combination.
Now if i < n, you iterate over all the elements in array A[i]. This gives you another part of the combination. Now call combinations(i+1) to get all combinations of the remaining arrays.
Finally combinations(0) gives all the combinations of all arrays.