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# 129. Sum Root to Leaf Numbers
from collections import deque
"""
given 'root' of binary tree containing digits 0-9 only. each root-to-leaf
pattern in the tree represents a number. eg. root-to-leaf path 1->2->3
represents the integer 123. return total sum of all root-to-leaf numbers.
test cases will fit in 32-bit integer. a leaf node is a node with no children
"""
# Definition for a binary tree node.
class TreeNode(object):
def __init__(self, val=0, left=None, right=None):
self.val = val
self.left = left
self.right = right
def from_list(data):
def create(it):
val = next(it)
return None if val is None else TreeNode(val)
if not data:
return None
it = iter(data)
root = TreeNode(next(it))
nextlevel = [root]
try:
while nextlevel:
level = nextlevel
nextlevel = []
for node in level:
if node:
node.left = create(it)
node.right = create(it)
nextlevel += [node.left, node.right]
except StopIteration:
return root
class Solution(object):
def sumNumbers(self, root):
"""
:type root: TreeNode
:rtype: int
"""
s, tot_sum = deque([(root, 0)]), 0
while len(s):
root, cur = s.pop()
cur *= 10 + root.val
if not root.left and not root.right:
tot_sum += cur
if root.right:
s.append((root.right, cur))
if root.left:
s.append((root.left, cur))
return tot_sum
if __name__ == "__main__":
r1, r2 = Solution(), Solution()
t1 = [1, 2, 3]
t2 = [4, 9, 0, 5, 1]
print(r1.sumNumbers(from_list(t1))) # expect: 25
print(r2.sumNumbers(from_list(t2))) # expect: 1026
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