c# - Multiknapsack algorithm - out of collection while trying to remove object -

i've encountered problem while working on multiknapsack solver. program working on 1 knapsack when comes multiple knaps there problems.

problem: items aren't removed collection. know need this, because second knapsack iterating again through same objects - maximized val same...

private void knapsack() {     list<plecak> descendingkanps = _plecaklist.orderbydescending(o => o.w).tolist(); // list of configured kanpsacks in descending order     list<produkt> descendingproducts = _produktlist.orderbydescending(o => o.cena).tolist(); // list of products pack in descending order     int n = descendingproducts.count; //number of items in product list     double maxval = 0; // accumulated value of 1 knapsack     foreach (plecak p in descendingkanps) // every knapsack...     {         double[,] v = new double[n + 1, (int)p.w + 1]; //array stores best option (the value of item)         (int c = 0; c <= p.w; c++) //since 0-1 mkp problem initialize whole array zeroes         {             v[0, c] = 0;         }         (int r = 0; r <= n; r++)         {             v[r, 0] = 0;         }          (int = 1; <= n; i++) // constraint of items count         {             (int wt = 1; wt <= p.w; wt++) //the constraint of weight             {                 if (descendingproducts[i - 1].waga < wt + 1) // if weight of product less constraint, can added...                     v[i, wt] = math.max(descendingproducts[i - 1].cena + v[i - 1, wt - descendingproducts[i - 1].waga], v[i - 1, wt]); // find best solution , add value value array, comapre value value form previous row                 else                     v[i, wt] = v[i - 1, wt]; // keep 0, or last best solution                  maxval = v[i, wt]; // assign variable             }         }         summary.items.add("maximum val knapsack: " + p.nazwa + " is: " + maxval); // print out value of knapsack     } } 

this turn answer, question.

in code have this:

for (int c = 0; c <= p.w; c++) //since 0-1 mkp problem initialize whole array zeroes {     v[0, c] = 0; } (int r = 0; r <= n; r++) {      v[r, 0] = 0; } 

you "initialize whole array zeroes". above code array:

 0 0 0 0 0 0 1 1 1 1 0 1 1 1 1 0 1 1 1 1 

you'll ever reach first column , top row. if places in array should changed 0, correct approach:

for (int r = 0; r <= n; r++) {     (int c = 0; c <= p.w; c++)      {         v[r, c] = 0;     } } 

i hope input can of help.