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Merge pull request #467 from Miraclelucy/master

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Update 0617.合并二叉树.md - 增加了python3版本的迭代解法
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程序员Carl
2021-07-06 21:54:12 +08:00
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parent c1ac306922 33f2e456a1
commit adb27f241c
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problems/0617.合并二叉树.md
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@ -319,7 +319,7 @@ Python：
# self.val = val
# self.left = left
# self.right = right
//递归法*前序遍历
# 递归法*前序遍历
class Solution:
def mergeTrees(self, root1: TreeNode, root2: TreeNode) -> TreeNode:
if not root1: return root2 // 如果t1为空，合并之后就应该是t2
@ -328,6 +328,32 @@ class Solution:
root1.left = self.mergeTrees(root1.left , root2.left) //左
root1.right = self.mergeTrees(root1.right , root2.right) //右
return root1 //root1修改了结构和数值
# 迭代法-覆盖原来的树
class Solution:
def mergeTrees(self, root1: TreeNode, root2: TreeNode) -> TreeNode:
if not root1: return root2
if not root2: return root1
# 迭代,将树2覆盖到树1
queue1 = [root1]
queue2 = [root2]
root = root1
while queue1 and queue2:
root1 = queue1.pop(0)
root2 = queue2.pop(0)
root1.val += root2.val
if not root1.left: # 如果树1左儿子不存在，则覆盖后树1的左儿子为树2的左儿子
root1.left = root2.left
elif root1.left and root2.left:
queue1.append(root1.left)
queue2.append(root2.left)
if not root1.right: # 同理，处理右儿子
root1.right = root2.right
elif root1.right and root2.right:
queue1.append(root1.right)
queue2.append(root2.right)
return root
```
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