Question

What’s the best algorithm to find the smallest non zero positive value from a fixed number (in this case 3) of values or return 0 if there are no positive questions?

My naive approach is below (in Delphi, but feel free to use whatever you like), but I think there’s a more elegant way.

value1Temp := MaxInt; value2Temp := MaxInt; value3Temp := MaxInt;  if ( value1T > 0) then   value1Temp := value1; if ( value2 > 0) then   value2Temp := value2; if ( value3 > 0) then   value3Temp  := value3;  Result := Min(value1Temp, Min(value2Temp, value3Temp)); if Result = MaxInt then   Result := 0; 

Edit: Sorry added what’s needed if there are no positive numbers. I thought I had it in there before, but must have missed it.

Answer 1

I’d do this:

Result := MaxInt;
if value1 > 0 then Result := min(Result, value1);
if value2 > 0 then Result := min(Result, value2);
if value3 > 0 then Result := min(Result, value3);
if Result = MaxInt then Result := 0;

If you want it in a loop with an arbitrary number of questions, then:

Result := MaxInt;
for I := 1 to N do
   if value[I] > 0 then Result := min(Result, value[I]);
if Result = MaxInt then Result := 0;

If you want the value array to be zero-based, change the for loop to be: 0 to N-1

I think this code makes it very clear exactly what is being done.

Putting the ‘then’ statements on the same line makes the code look cleaner in this simple case, but feel free to indent the ‘then’ statements onto the next line if you feel it’s necessary.