【树-简单】100. 相同的树-优快云博客

【题目】

【代码】
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class Solution:
    def preOrder(self,root,flag,depth):
        if not root:
            return
        self.a_pre[flag].append(str(root.val)+str(depth))
        self.preOrder(root.left,flag,depth+1)
        self.preOrder(root.right,flag,depth+1)
    
    def inOrder(self,root,flag,depth):
        if not root:
            return
        self.inOrder(root.left,flag,depth+1)
        self.b_in[flag].append(str(root.val)+str(depth))
        self.inOrder(root.right,flag,depth+1)

    def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
        self.a_pre=[[],[]]
        self.b_in=[[],[]]
        self.preOrder(p,0,0)
        self.preOrder(q,1,0)
        self.inOrder(p,0,0)
        self.inOrder(q,1,0)
        print(self.a_pre)
        print(self.b_in)
        return self.a_pre[0]==self.a_pre[1] and self.b_in[0]==self.b_in[1]

【简化版本】
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class Solution:
    def preOrder(self,root,flag,depth):
        if not root:
            return
        self.a_pre[flag].append(str(root.val)+str(depth))
        self.preOrder(root.left,flag,depth+1)
        self.b_in[flag].append(str(root.val)+str(depth))
        self.preOrder(root.right,flag,depth+1)
    
    def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
        self.a_pre=[[],[]]
        self.b_in=[[],[]]
        self.preOrder(p,0,0)
        self.preOrder(q,1,0)
        return self.a_pre[0]==self.a_pre[1] and self.b_in[0]==self.b_in[1]

【广度优先】
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class Solution:
    def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
        if not p or not q:
            return p==q
        ans=[[],[]]
        loc=[[],[]]
        def deal(flag):
            depth=0
            while queue_p:
                sz=len(queue_p)
                for i in range(sz):
                    node=queue_p.pop(0)
                    print(node.val)
                    ans[flag].append((node.val,depth))
                    if node.left:
                        queue_p.append(node.left)
                        loc[flag].append(0)
                    if node.right:
                        queue_p.append(node.right)
                        loc[flag].append(1)
                depth+=1
        queue_p=[p]
        deal(0)
        queue_p=[q]
        deal(1)
        return ans[0]==ans[1] and loc[0]==loc[1]

【方法4】
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class Solution:
    def preOrder(self,p,q):
        if not p or not q:
            return p is None and q is None
        elif p.val!=q.val:
            return False
        return self.preOrder(p.left, q.left) and self.preOrder(p.right,q.right)
    
    def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
        return self.preOrder(p,q)

【方法5】
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class Solution:
    def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
        if not p or not q:
            return not p and not q
        elif p.val!=q.val:
            return False
        return self.isSameTree(p.left,q.left) and self.isSameTree(p.right,q.right)