multiplication of C# lists -

i having brain freeze , cant figure out solution problem.

i created class called customset contained string list. class holding reference customset stores list.

public class customset : ienumerable<string> {     public string name { get; set; }     internal ilist<string> elements;      public customset(string name)     {         this.name = name;         this.elements = new list<string>();     }      public ienumerable<string> elements     {                 {             return elements;         }     }     public ienumerator<string> getenumerator()     {         return elements.getenumerator();     }     ienumerator ienumerable.getenumerator()     {         return getenumerator();     } } 

so iterate on list of custom sets out put 2d string array columns number of customset(s) , rows multiplication of customset elements.

as example, if there 3 custom sets in list: 1st had 3 elements, 2nd had 2 elements , 3rd had 3 elements. want output 3 columns , 18 rows (3*2*3). following code attempt @ solution:

customset motion = new customset("motion"); motion.elements.add("low"); motion.elements.add("medium"); motion.elements.add("high");  customset speed = new customset("speed"); speed.elements.add("slow"); speed.elements.add("fast");  customset mass = new customset("mass"); mass.elements.add("light"); mass.elements.add("medium"); mass.elements.add("heavy");  list<customset> aset = new list<customset>(); aset.add(motion); aset.add(speed); aset.add(mass);  //problem code int rows = 1; for(int = 0; < aset.count; i++) {     rows *= aset[i].elements.count; }  string[,] array = new string[aset.count, rows]; int modulus;  (int = 0; < aset.count; i++) {     (int j = 0; j < rows; j++)     {         modulus = j % aset[i].elements.count;         array[i, j] = aset[i].elements[modulus];     } }  (int j = 0; j < rows; j++) {     (int = 0; < aset.count; i++)     {         console.write(array[i, j] + " / ");     }     console.writeline(); } //end  console.readline(); 

however, code not output correct string array (though close). out put following:

low / slow / light /

low / slow / medium /

low / slow / heavy /

low / fast / light /

low / fast / medium /

low / fast / heavy /

medium / slow / light /

medium / slow / medium /

medium / slow / heavy /

medium / fast / light /

medium / fast / medium /

medium / fast / heavy /

high / slow / light /

high / slow / medium /

high / slow / heavy /

high / fast / light /

high / fast / medium /

high / fast / heavy /

now variables in problem number of customsets in list , number of elements in each customset.

you can product in 1 go:

var crossjoin = m in motion                 s in speed                 ms in mass                 select new { motion = m, speed = s, mass = ms };  foreach (var val in crossjoin) {    console.write("{0} / {1} / {2}", val.motion, val.speed, val.mass); } 

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now, since don't know number of lists, need more. eric lippert covers in this article, can use certesianproduct function defined there in following manner:

var cproduct = somecontainerclass.cartesianproduct(aset.select(m => m.elements)); var stringstooutput = cproduct.select(l => string.join(" / ", l));