Cammat.bas

function Cammat1(n as integer) as LongInt
    if n <= 2 then return n+1

    dim as LongInt c(n)
    c(0) = 1: c(1) = 2: c(2) = 3

    for i as integer = 3 to n
        dim as integer sigmaVal = 0
        for k as integer = 0 to (i-2)\2
            if (k AND 1) then
                sigmaVal -= c((i-2)-2*k)
            else
                sigmaVal += c((i-2)-2*k)
            end if
        next k
        c(i) = c(i-1) + sigmaVal
    next i

    return c(n)
end function

function Cammat2(n as integer) as LongInt
    if n <= 2 then return n+1

    dim as LongInt c(n)
    c(0) = 1: c(1) = 2: c(2) = 3

    for i as integer = 3 to n
        dim as integer sigmaVal = 0, sign = 1
        for k as integer = 0 to (i-2)\2
            sigmaVal += sign * c((i-2)-2*k)
            sign = -sign
        next k
        c(i) = c(i-1) + sigmaVal
    next i

    return c(n)
end function

dim as double startTime, endTime
dim as LongInt result

startTime = timer
for x as integer = 0 to 5000
    result = Cammat1(35)
next x
endTime = timer

print "Cammat (if / else):"
print result, endTime-startTime

startTime = timer
for x as integer = 0 to 5000
    result = Cammat2(35)
next x
endTime = timer

print "Cammat (sign * result):"
print result, endTime-startTime
sleep