/// <summary>
/// Estimates the signed serialize size of an unsigned transaction, assuming all
/// inputs spend P2PKH outputs. The estimate is a worst case, so the actual
/// serialize size after signing should always be less than or equal to this value.
/// </summary>
/// <param name="inputCount">Number of P2PKH outputs the transaction will redeem</param>
/// <param name="outputs">Transaction output array</param>
/// <param name="addChangeOutput">Add the serialize size for an additional P2PKH change output</param>
/// <returns>Estimated signed serialize size of the transaction</returns>
public static int EstimateSerializeSize(int inputCount, Output[] outputs, bool addChangeOutput)
{
if (outputs == null)
throw new ArgumentNullException(nameof(outputs));
var changeSize = 0;
var outputCount = outputs.Length;
if (addChangeOutput)
{
changeSize = PayToPubKeyHashOutputSize;
outputCount++;
}
return
12 + (2 * CompactInt.SerializeSize((ulong)inputCount)) + CompactInt.SerializeSize((ulong)outputCount) +
inputCount * RedeemPayToPubKeyHashInputSize +
outputs.Sum(o => o.SerializeSize) +
changeSize;
}