public int MaxProfit(int[] prices)
{
possibleSolution currentBest = null;
possibleSolution buildingSolution = null;
for (int i = 0; i < prices.Length; i++)
{
findAnyNewBetterSolutionBeatCurrentBest(ref buildingSolution, ref currentBest, prices[i], i);
}
if (currentBest == null)
{
currentBest = buildingSolution;
}
if (buildingSolution != null && buildingSolution.GetProfit() > currentBest.GetProfit())
{
currentBest = buildingSolution;
}
if (currentBest == null || currentBest.GetProfit() < 0)
{
return(0);
}
return(currentBest.GetProfit());
}
private void findAnyNewBetterSolutionBeatCurrentBest(ref possibleSolution buildingSolution, ref possibleSolution currentBest, int v, int i)
{
if (buildingSolution == null)
{
buildingSolution = new possibleSolution();
}
if (!buildingSolution.hasBuyPrice)
{
//no buy price, use current one;
buildingSolution.setBuyPrice(v, i);
return;
}
if (buildingSolution.LowP > v)
{
if (buildingSolution.hasSellPrice)
{
//has both buy and sell
//check profit with best one
if (currentBest == null || currentBest.GetProfit() < buildingSolution.GetProfit())
{
//if is better solution, replace exsiting one.
currentBest = buildingSolution;
}
//clean current building Solution, setup new one
buildingSolution = new possibleSolution();
buildingSolution.setBuyPrice(v, i);
return;
}
else
{
//no buy price. simple set new price as sell price
buildingSolution.setBuyPrice(v, i);
return;
}
}
if (!buildingSolution.hasSellPrice || buildingSolution.HighP < v)
{
buildingSolution.setSellPrice(v, i);
return;
}
}