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@matugm
Created June 17, 2015 14:29
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class ListNode
attr_accessor :val, :next
def initialize(val)
@val = val
@next = nil
end
end
@carry = false
def add_nodes(l1,l2)
total = l1.val + l2.val
if @carry
total += 1
@carry = false
end
if total > 9
total = total % 10
@carry = true
end
create_node(total)
end
def add_two_numbers(l1, l2)
@carry = false
add_two_numbers_real(l1, l2)
end
def add_two_numbers_real(l1, l2)
return create_node(1) if @carry and !l1
return unless l1 or l2
l2 = create_node(0) unless l2
l1 = create_node(0) unless l1
node = add_nodes(l1, l2)
node.next = add_two_numbers_real(l1.next, l2.next)
node
end
module List
def create_list(values)
recursive_append_multiple(values)
# head = create_node(values.shift)
# values.each { |n| head = append_node(head, n) }
# head
end
def create_node(value)
ListNode.new value
end
def recursive_append_multiple(values, idx = 0)
return if idx >= values.size
node = create_node(values[idx])
node.next = recursive_append_multiple(values, idx+1)
node
end
# Loop until node.next = nil
def append_node(node, value)
node.tap {
while node.next
node = node.next
end
node.next = create_node(value)
}
end
end
include List
list_1 = create_list [3,2,1]
list_2 = create_list [3,2,1]
one = create_list [1]
five = create_list [5]
list_3 = create_list [1,8]
zero = create_list [0]
p add_two_numbers one, five
p add_two_numbers five, five
p add_two_numbers list_1, list_2
p add_two_numbers list_3, zero
p add_two_numbers create_list([9]), create_list([9])
p add_two_numbers create_list([9,9]), create_list([1])
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