Find combinations in arrays

I have an 2D-array like this in java

transmission communication tv television  
approach     memorycode  
methodact

开发者_高级运维

I need to get all combinations like:

{transmission,approach,methodact},{transmission,memorycode,methodact},{communication,approach,methodact},...

Can someone provide an example that will work for nXn arrays, even if it has only two rows?

---

This should do the trick:

static Set<List<String>> allComb(String[][] opts) {

    Set<List<String>> results = new HashSet<List<String>>();

    if (opts.length == 1) {
        for (String s : opts[0])
            results.add(new ArrayList<String>(Arrays.asList(s)));
    } else
        for (String str : opts[0]) {
            String[][] tail = Arrays.copyOfRange(opts, 1, opts.length);
            for (List<String> combs : allComb(tail)) {
                combs.add(str);
                results.add(combs);
            }
        }
    return results;
}

---

This code in JavaScript can help you:

var sampleArray = [["transmission","communication","tv","television"], ["approach","memorycode"], ["methodact"]];

var GetAllCombinations = function(array2d) {

var ret=[];

var fn = function(arr,index,cur)
{
    var ret = [];
    for (var i=0; i<arr[index].length; i++)
    {
        var x = cur.slice(0);
        x.push(arr[index][i]);
        if (index == arr.length-1)
            ret.push(x);
        else
            ret = ret.concat(fn(arr,index+1,x));
    }
    return ret;
};
return fn(array2d,0,[]);

} console.log(GetAllCombinations(sampleArray));

It builds all combinations starting with a given array, iterates over all the options for that level and call it recursively, then concatenate it with the result.