RandomKSubset
RandomKSubset[l,k]
gives a random subset of set 
with exactly 
elements.
Combinatorica`
Combinatorica`
RandomKSubset
RandomKSubset[l,k]
gives a random subset of set 
with exactly 
elements.
更多信息和选项
- To use RandomKSubset, you first need to load the Combinatorica Package using Needs["Combinatorica`"].