ChrisLundquist

#!/usr/bin/env ruby

def find_pair!(data, target)
  # We know we won't use a value greater than our target
  data.reject! { |i| i > target }
  
  # Sort it so we don't have to scan our list a bunch
  data.sort!
  
  # If our two biggest numbers are lower than the target, we're boned

ChrisLundquist

//
//  fs_capabilities.m
//
//  Created by Charles Francoise on 13/05/14.
//  Copyright (c) 2014 Charles Francoise. All rights reserved.
//

#include <stdio.h>
#include <unistd.h>
#include <errno.h>

ChrisLundquist

//
//  fs_capabilities.m
//
//  Created by Charles Francoise on 13/05/14.
//  Copyright (c) 2014 Charles Francoise. All rights reserved.
//

#include <stdio.h>
#include <unistd.h>
#include <errno.h>

ChrisLundquist

#!/usr/bin/env ruby
# The number, 197, is called a circular prime because all rotations of the digits: 197, 971, and 719, are themselves prime.
# There are thirteen such primes below 100: 2, 3, 5, 7, 11, 13, 17, 31, 37, 71, 73, 79, and 97.
#How many circular primes are there below one million?
#
require 'prime'

candidates = [2] + Prime.each(1_000_000).reject { |p| p.digits.any? { |d| d.even? } }

def siblings(int)