提交作业

8-homework-yanjun/tree_depth.py

+class node():
+    def __init__(self, k=None, l=None, r=None):
+        self.val = k
+        self.left = l
+        self.right = r
+
+
+def listcreattree(root, llist, i):
+    if i < len(llist):
+        if llist[i] == 'null':
+            return None  ###这里的return很重要
+        else:
+            root = node(k=llist[i])
+            # print(llist[i])
+            root.left = listcreattree(root.left, llist, 2 * i + 1)
+            root.right = listcreattree(root.right, llist, 2 * i + 2)
+            return root  ###这里的return很重要
+    return root
+
+
+def tree_depth(root):
+    if root == None:
+        return 0
+    #最大深度
+    return max(tree_depth(root.left), tree_depth(root.right)) + 1
+    # return min(tree_depth(root.left), tree_depth(root.right)) + 1 最小深度
+
+
+if __name__ == '__main__':
+    root = node()
+    # llist = ['1', '2', '3', '#', '4', '5']
+    llist = [3, 9, 20, 'null', 'null', 15, 7]
+    root = listcreattree(root, llist, 0)
+    result = tree_depth(root)
+    print(result)