Maximize profit on a trade route

Fixed trade route with goods and prices and fixed cargo capacity.

How can I optimize profit?

No cost to trade or transport - just fixed capacity, route, and prices. All products use the same capacity, which is kind of artificial, but this is just a single pass starting with an empty vessel. It does a semi brute force on all possible trades

The example would be 3 port and 3 products, like apples, pears, and oranges trading at various prices.

Test:

Int32[,] portsProducts = new Int32[,] { { 1, 1, 1 }, { 2, 1, 1 }, { 4, 2, 3 } };
Int32[,]  answer = PortsProducts(portsProducts);

Code:

```
public static Int32[,] PortsProducts(Int32[,] portsProducts)
{
int rowCount = portsProducts.GetLength(0);
int colCount = portsProducts.GetLength(1);
Int32[,] buySell = new Int32[rowCount, colCount];
Int32[,] buySellMax = new Int32[rowCount, colCount];
Int32[] highPrice = new Int32[colCount];
Int32[] lowPrice = new Int32[colCount];

List rowDisplay = new List();
Debug.WriteLine("portsProducts");
for (int i = 0; i portsProducts[i, j])
lowPrice[j] = portsProducts[i, j];
}
}
}

// build up a matrix of all possible buy sell hold for next rowCount - 1
// 0 hold, 1 is sell, 2 buy
List allBuySellOptions = new List ();
Int32[,] buySellOptions = new Int32[rowCount, colCount];
//Int32[,] buySellOptionsOld = new Int32[rowCount - 1, colCount];
for (int i = 0; i 0)
{ // sell
// sell first to clear capacity
profit += curProduct[j] * portsProducts[i, j];
curCapacity += curProduct[j];
buySell[i, j] = -curProduct[j];
curProduct[j] = 0;
}
else if(buySellOpt[i, j] == 1)
{
buyCount++;
}
}
if (buyCount > 0 && c

Code organization

PortsProducts is one gigantic method. I suggest to decompose it to many small methods that each have a single clear responsibility, with a descriptive method name.

Mutually exclusive conditions

portsProducts[i, j] will never be higher than the highest prices and lower than the lowest at the same time, so the 2nd if statement here should be an else if:

if (highPrice[j]  portsProducts[i, j])
    lowPrice[j]  = portsProducts[i, j];

Use more helper variables

In the buySellBump2 method there are many references to buySellOptions[i, j] and portsProducts[i, j].
It would be easier to write and to read if you put those in local helper variables.

StackExchange Code Review Q#150832, answer score: 5