Add Two Numbers
Helper function을 두개 써서.. 1) LL to integer 2) integer to LL
바꾸고, 더하고, 다시 바꾸면.. O(n) 이 되겠시며.
# Definition for singly-linked list.
# class ListNode(object):
# def __init__(self, x):
# self.val = x
# self.next = None
class Solution(object):
def parseList(self, ll):
num = 0
iter = ll
power = 0
while True:
num += iter.val * (10 ** power)
if iter.next is None:
break
else:
iter = iter.next
power += 1
return num
def numToList(self, num):
l = ListNode(num % 10)
iter = l
num /= 10
while num > 0:
iter.next = ListNode(num % 10)
iter = iter.next
num /= 10
return l
def addTwoNumbers(self, l1, l2):
"""
:type l1: ListNode
:type l2: ListNode
:rtype: ListNode
"""
'''
1) parse lists into number
2) convert the sum into linked list and return
'''
num1 = self.parseList(l1)
num2 = self.parseList(l2)
sum = num1 + num2
print num1, "+", num2, "=", sum
return self.numToList(sum)
