LintCodeInPython/binary-tree-level-sum.py at master · yingl/LintCodeInPython · GitHub

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"""
Definition of TreeNode:
class TreeNode:
 def __init__(self, val):
 self.val = val
 self.left, self.right = None, None
"""

classSolution:
"""
 @param root: the root of the binary tree
 @param level: the depth of the target level
 @return: An integer
 """
deflevelSum(self, root, level):
# write your code here
ret=0
ifrootand (level>0):
ilevel=1
curr_nodes= [root]
next_nodes= []
whileilevel<level:
fornodeincurr_nodes:
ifnode.left:
next_nodes.append(node.left)
ifnode.right:
next_nodes.append(node.right)
ilevel+=1
curr_nodes=next_nodes
next_nodes= []
fornodeincurr_nodes:
ret+=node.val
returnret

# easy: https://www.lintcode.com/problem/binary-tree-level-sum/