public int WaysToShare(Stack2 coins)
{
#if DEBUG
if (coins.Sum() % 2 != 0)
{
throw new Exception($"Unexpected sum of coins - should be even number - received {coins.Sum()}");
}
#endif
// even, with only one set of coins ... one way to share - split down middle.
if (coins.Count() == 1)
{
return(1);
}
// extract even amounts from odd
var(even, odd) = coins.SplitEvenOdd();
if (odd.Count() % 2 == 1)
{
throw new Exception("Count of odd items is odd - which should not be the case");
}
return(MergeBlocks(MergeBlocks(even), MergeBlocks(odd)));
}
public void Process(int value, ref Int64 total, int remainder, Stack2 state)
{
if (remainder != 0)
{
if (parent == null)
{
if (remainder > 0)
{
if (remainder % Head == 0)
{
var tc = remainder / Head + state.Sum();
if (tc % 2 == 0)
{
state.Push(remainder / Head);
total += new ShareCoinsEvenly(100).WaysToShare(state);
state.Pop();
}
}
}
}
else
{
if (SupportsCache())
{
if (cache[remainder] == null)
{
cache[remainder] = new int[maxValue];
}
cache[remainder][state.Sum()]++;
}
else
{
for (int i = 1; i <= remainder / Head; i++)
{
state.Push(i);
parent.Process(value, ref total, remainder - i * Head, state);
state.Pop();
}
}
}
}
}
