problem7.jl for debugging jocco

problem7.jl

# in problem7.jl

# find the 10,001st prime number

# isPrime(n) uses the sieve of Eratosthenes

# Test LaTeX
# Using [Pandoc] allows us to have math inline $x=y$ or in display mode
# $$
#   \begin{aligned}
#     \nabla \times \vec{\mathbf{B}} -\, \frac1c\,
#     \frac{\partial\vec{\mathbf{E}}}{\partial t} &=
#     \frac{4\pi}{c}\vec{\mathbf{j}} \\
#     \nabla \cdot \vec{\mathbf{E}} &= 4 \pi \rho \\
#     \nabla \times \vec{\mathbf{E}}\, +\, \frac1c\,
#     \frac{\partial\vec{\mathbf{B}}}{\partial t} &= \vec{\mathbf{0}} \\
#     \nabla \cdot \vec{\mathbf{B}} &= 0
#   \end{aligned}
# $$
# if you wish.  This uses the [MathJax] Content Distribution Network script to
# turn $\LaTeX$ source into rendered output and thus an internet connection is
# required.  [MathJax] may be installed locally if offline access is desired.
#
# @Knuth:1984:LP might be something we should read when building a literate
# programming tool.  We can also reference this in a note.[^1]
#
# This [Julia] port of [Docco] is roughly structured the same as the [Lua]
# port [Locco].  Its source is released in the public domain and is available
# on [GitHub](http://github.com/lcw/jocco).

function isPrime(n)
  if n == 1
		return false
	
	elseif n < 4
		return true
		
	elseif mod(n,2) == 0
		return false
		
	elseif n < 9
		return true
		
	elseif mod(n,3) == 0
		return false
		
	else
		r = floor(sqrt(n))
		f = 5
		while f <= r
			if mod(n,f) == 0 
				return false
			elseif mod(n,f+2) == 0
				return false
			else
				f += 6
			end
		end
	end
	return true
end

limit = 10001
count = 1
candidate = 1
while count != limit
	candidate += 2
	if isPrime(candidate)
		count += 1
	end
end
println(candidate)