Task: Knapsack problem_0-1



C#: using System;
using System.Collections.Generic;

namespace Tests_With_Framework_4
{

class Bag : IEnumerable<Bag.Item>
        {
            List<Item> items;
            const int MaxWeightAllowed = 400;

            public Bag()
            {
                items = new List<Item>();
            }

            void AddItem(Item i)
            {
                if ((TotalWeight + i.Weight) <= MaxWeightAllowed)
                    items.Add(i);
            }

            public void Calculate(List<Item> items)
            {
                foreach (Item i in Sorte(items))
                {
                    AddItem(i);
                }
            }

            List<Item> Sorte(List<Item> inputItems)
            {
                List<Item> choosenItems = new List<Item>();
                for (int i = 0; i < inputItems.Count; i++)
                {
                    int j = -1;
                    if (i == 0)
                    {
                        choosenItems.Add(inputItems[i]);
                    }
                    if (i > 0)
                    {
                        if (!RecursiveF(inputItems, choosenItems, i, choosenItems.Count - 1, false, ref j))
                        {
                            choosenItems.Add(inputItems[i]);
                        }
                    }
                }
                return choosenItems;
            }

            bool RecursiveF(List<Item> knapsackItems, List<Item> choosenItems, int i, int lastBound, bool dec, ref int indxToAdd)
            {
                if (!(lastBound < 0))
                {
                    if ( knapsackItems[i].ResultWV < choosenItems[lastBound].ResultWV )
                    {
                        indxToAdd = lastBound;
                    }
                    return RecursiveF(knapsackItems, choosenItems, i, lastBound - 1, true, ref indxToAdd);
                }
                if (indxToAdd > -1)
                {
                    choosenItems.Insert(indxToAdd, knapsackItems[i]);
                    return true;
                }
                return false;
            }

            #region IEnumerable<Item> Members
            IEnumerator<Item> IEnumerable<Item>.GetEnumerator()
            {
                foreach (Item i in items)
                    yield return i;
            }
            #endregion

            #region IEnumerable Members
            System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
            {
                return items.GetEnumerator();
            }
            #endregion

            public int TotalWeight
            {
                get
                {
                    var sum = 0;
                    foreach (Item i in this)
                    {
                        sum += i.Weight;
                    }
                    return sum;
                }
            }

            public class Item
            {
                public string Name { get; set; } public int Weight { get; set; } public int Value { get; set; } public int ResultWV { get { return  Weight-Value; } }
                public override string ToString()
                {
                    return "Name : " + Name + "        Wieght : " + Weight + "       Value : " + Value + "     ResultWV : " + ResultWV;
                }
            }
        }

    class Program
    {
        static void Main(string[] args)
        {List<Bag.Item> knapsackItems = new List<Bag.Item>();
            knapsackItems.Add(new Bag.Item() { Name = "Map", Weight = 9, Value = 150 });
            knapsackItems.Add(new Bag.Item() { Name = "Water", Weight = 153, Value = 200 });
            knapsackItems.Add(new Bag.Item() { Name = "Compass", Weight = 13, Value = 35 });
            knapsackItems.Add(new Bag.Item() { Name = "Sandwitch", Weight = 50, Value = 160 });
            knapsackItems.Add(new Bag.Item() { Name = "Glucose", Weight = 15, Value = 60 });
            knapsackItems.Add(new Bag.Item() { Name = "Tin", Weight = 68, Value = 45 });
            knapsackItems.Add(new Bag.Item() { Name = "Banana", Weight = 27, Value = 60 });
            knapsackItems.Add(new Bag.Item() { Name = "Apple", Weight = 39, Value = 40 });
            knapsackItems.Add(new Bag.Item() { Name = "Cheese", Weight = 23, Value = 30 });
            knapsackItems.Add(new Bag.Item() { Name = "Beer", Weight = 52, Value = 10 });
            knapsackItems.Add(new Bag.Item() { Name = "Suntan Cream", Weight = 11, Value = 70 });
            knapsackItems.Add(new Bag.Item() { Name = "Camera", Weight = 32, Value = 30 });
            knapsackItems.Add(new Bag.Item() { Name = "T-shirt", Weight = 24, Value = 15 });
            knapsackItems.Add(new Bag.Item() { Name = "Trousers", Weight = 48, Value = 10 });
            knapsackItems.Add(new Bag.Item() { Name = "Umbrella", Weight = 73, Value = 40 });
            knapsackItems.Add(new Bag.Item() { Name = "WaterProof Trousers", Weight = 42, Value = 70 });
            knapsackItems.Add(new Bag.Item() { Name = "Note-Case", Weight = 22, Value = 80 });
            knapsackItems.Add(new Bag.Item() { Name = "Sunglasses", Weight = 7, Value = 20 });
            knapsackItems.Add(new Bag.Item() { Name = "Towel", Weight = 18, Value = 12 });
            knapsackItems.Add(new Bag.Item() { Name = "Socks", Weight = 4, Value = 50 });
            knapsackItems.Add(new Bag.Item() { Name = "Book", Weight = 30, Value = 10 });
            knapsackItems.Add(new Bag.Item() { Name = "waterproof overclothes ", Weight = 43, Value = 75 });

            Bag b = new Bag();
            b.Calculate(knapsackItems);
            b.All(x => { Console.WriteLine(x); return true; });
            Console.WriteLine(b.Sum(x => x.Weight));
            Console.ReadKey();
        }
    }
}




PHP: #########################################################
# 0-1 Knapsack Problem Solve with memoization optimize and index returns
# $w = weight of item
# $v = value of item
# $i = index
# $aW = Available Weight
# $m = Memo items array
# PHP Translation from Python, Memoization,
# and index return functionality added by Brian Berneker
#
#########################################################

function knapSolveFast2($w, $v, $i, $aW, &$m) {

	global $numcalls;
	$numcalls ++;


	if (isset($m[$i][$aW])) {
		return array( $m[$i][$aW], $m['picked'][$i][$aW] );
	} else {

		if ($i == 0) {
			if ($w[$i] <= $aW) { // Will this item fit?
				$m[$i][$aW] = $v[$i]; // Memo this item
				$m['picked'][$i][$aW] = array($i); // and the picked item
				return array($v[$i],array($i)); // Return the value of this item and add it to the picked list

			} else {

				$m[$i][$aW] = 0; // Memo zero
				$m['picked'][$i][$aW] = array(); // and a blank array entry...
				return array(0,array()); // Return nothing
			}
		}	


		list ($without_i, $without_PI) = knapSolveFast2($w, $v, $i-1, $aW, $m);

		if ($w[$i] > $aW) { // Does it return too many?
			
			$m[$i][$aW] = $without_i; // Memo without including this one
			$m['picked'][$i][$aW] = $without_PI; // and a blank array entry...
			return array($without_i, $without_PI); // and return it

		} else {

			list ($with_i,$with_PI) = knapSolveFast2($w, $v, ($i-1), ($aW - $w[$i]), $m);
			$with_i += $v[$i];  // ..and add the value of this one..

			if ($with_i > $without_i) {
				$res = $with_i;
				$picked = $with_PI;
				array_push($picked,$i);
			} else {
				$res = $without_i;
				$picked = $without_PI;
			}
						
			$m[$i][$aW] = $res; // Store it in the memo
			$m['picked'][$i][$aW] = $picked; // and store the picked item
			return array ($res,$picked); // and then return it
		}	
	}
}



$items4 = array("map","compass","water","sandwich","glucose","tin","banana","apple","cheese","beer","suntan cream","camera","t-shirt","trousers","umbrella","waterproof trousers","waterproof overclothes","note-case","sunglasses","towel","socks","book");
$w4 = array(9,13,153,50,15,68,27,39,23,52,11,32,24,48,73,42,43,22,7,18,4,30);
$v4 = array(150,35,200,160,60,45,60,40,30,10,70,30,15,10,40,70,75,80,20,12,50,10);

## Initialize
$numcalls = 0; $m = array(); $pickedItems = array();

## Solve
list ($m4,$pickedItems) = knapSolveFast2($w4, $v4, sizeof($v4) -1, 400, $m);

# Display Result 
echo "<b>Items:</b><br>".join(", ",$items4)."<br>";
echo "<b>Max Value Found:</b><br>$m4 (in $numcalls calls)<br>";
echo "<b>Array Indices:</b><br>".join(",",$pickedItems)."<br>";


echo "<b>Chosen Items:</b><br>";
echo "<table border cellspacing=0>";
echo "<tr><td>Item</td><td>Value</td><td>Weight</td></tr>";
$totalVal = $totalWt = 0;
foreach($pickedItems as $key) {
	$totalVal += $v4[$key];
	$totalWt += $w4[$key];
	echo "<tr><td>".$items4[$key]."</td><td>".$v4[$key]."</td><td>".$w4[$key]."</td></tr>";
}
echo "<tr><td align=right><b>Totals</b></td><td>$totalVal</td><td>$totalWt</td></tr>";
echo "</table><hr>";