Project Euler 003

gistfile1.txt

reltime: 54.894354

p003.vim

function! P003()
  let l:start = reltime()
  let l:num = StringToBigint("600851475143")
  let l:primes = Factorize(l:num)
  for i in l:primes
    echo BigintToString(i)
  endfor
  echo reltimestr(reltime(l:start))
endfunction

function! Factorize(num)
  let l:primes = []
  let l:n = deepcopy(a:num)
  let l:a = StringToBigint("2")
  while 1
    while 1
      let l:tmp = BigMod(l:n, l:a)
      if BigCompare(l:tmp, StringToBigint("0")) == 0
        let l:n = BigDiv(l:n, l:a)
        call add(primes, l:a)
      else
        break
      endif
    endwhile
    if BigCompare(l:n, StringToBigint("1")) == 0
      break
    endif
    let l:a = BigAdd(l:a, StringToBigint("1"))
  endwhile
  return l:primes
endfunction