private int Solve(int itemNumbers, int capacity)
{
if (itemNumbers == 0 /*|| capacity <= 0*/) // stop if capacity is 0 supposes that there is no item with weight 0
{
return(0);
}
var key = new KnapSackKey(itemNumbers, capacity);
if (Memoization.ContainsKey(key))
{
return(Memoization[key]);
}
var item = Items[itemNumbers - 1];
int takeItem = item.Weight <= capacity
? Solve(itemNumbers - 1, capacity - item.Weight) + item.Value
: 0;
int dropItem = Solve(itemNumbers - 1, capacity);
int greaterValue = Math.Max(takeItem, dropItem);
Memoization[key] = greaterValue;
return(greaterValue);
}
public void MemoizeLast()
{
var calls = 0;
var f = Memoization.MemoizeLast(delegate(int i) { calls++; return(i * 2); });
Assert.Equal(4, f(2));
Assert.Equal(1, calls);
Assert.Equal(4, f(2));
Assert.Equal(1, calls);
Assert.Equal(8, f(4));
Assert.Equal(2, calls);
}
public void MemoizeLastWithCustomComparer()
{
var calls = 0;
var comparer = StringComparer.OrdinalIgnoreCase;
var f = Memoization.MemoizeLast(delegate(string s) { calls++; return(s.ToUpperInvariant()); }, comparer);
Assert.Equal("FOOBAR", f("foobar"));
Assert.Equal(1, calls);
Assert.Equal("FOOBAR", f("FOOBAR"));
Assert.Equal(1, calls);
Assert.Equal("FOOBAR", f("FoObAr"));
Assert.Equal(1, calls);
}
static void Main(string[] args)
{
//var input = new int[] { 0, 2, 3, 5, 7, 11 };
//var input = new int[] { 1, 4, 6, 8, 9, 13, 18 };
//var input = new int[] { 2, 5, 5, 2 };
//var input = new int[] { 9, 4, 6, 20, 100, 15, 1 };
//var input = new int[] { 100, 20, 15, 9, 4, 6, 1 };
//var input = new int[] { 41, 72, 91, 50, 46, 68, 78, 99, 74, 89, 97, 84, 95, 41, 50 };
//all datastructures can be called like this
//var ds = new Graph<int>();
//var arr = new DynamicArray<int>();
//all algorithms can be called like this
var result = Memoization.FibonacciMemoized(35);
}
public void Test2()
{
var counter = 0;
var fib = YCombinator <int> .Fix(f => x =>
{
counter++;
return(x < 2 ? 1 : f(x - 1) + f(x - 2));
});
var m_fib = Memoization.Create(fib);
counter = 0;
m_fib(7);
Assert.Equal(41, counter);
counter = 0;
m_fib(7);
Assert.Equal(0, counter);
}
public void MemoizeLastWithNullInputComparer()
{
var f = Memoization.MemoizeLast <object, object>(_ => null, null);
Assert.Null(f(new object()));
}
public void MemoizeLastThrowsWithNullFunction()
{
var e = Assert.Throws <ArgumentNullException>(() => Memoization.MemoizeLast <object, object>(null));
Assert.Equal("function", e.ParamName);
}
public void Init()
{
sut = new Recursion();
sutMe = new Memoization();
}
