algorithms.rb

arr = [45, 234, 56758, 23, 1, 0, 0, 0, 0, 345345, 23]


def find_number(numbers, number)
    numbers.each_with_index do |n, i|
        if n == number
            return i
        end
    end

    return nil
end


arr = [45, 234, 56758, 23, 1, 0, 23, 0, 45, 345345, 23]

def find_duplicates(numbers)
    # find all numbers that occur more than once
    duplicates = {}
    
    numbers.each_with_index do |num|
        if !duplicates.has_key?(num)
            duplicates[num] = {
                "value": num,
                "num_occurences": 1,
            }
        else
            duplicates[num][:num_occurences] += 1
        end
    end

    return duplicates.select do |key, val|
        val[:num_occurences] > 1
    end
end


arr = []

1000.times do |i|
    arr << i * 2
end

def find_number_sorted(numbers, number)
    middle = (numbers.length / 2)

    puts
    puts "#{middle}, #{numbers[middle]}"

    if numbers[middle] == number
        return true
    elsif numbers.length <= 1
        return false
    elsif numbers[middle] > number
        return find_number_sorted(numbers[0..(middle-1)], number)
    else
        return find_number_sorted(numbers[middle..(numbers.length-1)], number)
    end

end

puts find_number_sorted(arr, 1998)



def parseInt(string)
    integer = 0

    digits = string.split("")
    digits.each_with_index do |digit, pos|
        multiplier = 10**(digits.length - pos - 1)
        digit = digits[pos]

        case digit
            when "0"
                i = 0
            when "1"
                i = 1
            when "2"
                i = 2
            when "3"
                i = 3
            when "4"
                i = 4
            when "5"
                i = 5
            when "6"
                i = 6
            when "7"
                i = 7
            when "8"
                i = 8
            when "9"
                i = 9
            else
                i = nil
        end

        integer += i * multiplier
    end

    return integer
end