pta上代码提交后非零返回

class BinNode:
    def __init__(self, data):
        self.data = data
        self.left = None
        self.right = None

class BinTree:
    def __init__(self, data):
        self.root = BinNode(data)

def create(r, x, i):
    if x[i] != '0':
        r.left = BinNode(x[i])
        i = create(r.left, x, i + 1)
    i = i + 1
    if x[i] != '0':
        r.right = BinNode(x[i])
        i = create(r.right, x, i + 1)
    return i

def dfs(x, root):
    if root is None:
        return
    if (root.left and root.left.data == x) or (root.right and root.right.data == x):
        return root
    result = dfs(x, root.left)
    if result:
        return result
    return dfs(x, root.right)

inputString = input().replace('','')
tree = BinTree(inputString[0])
create(tree.root, inputString, 1)
arr = [0 for x in range(0, 100)]
m = int(input())
if m < 100:
    for i in range(m):
        k = input()
        arr[i] = k

    for i in range(m):
        b = dfs(arr[i], tree.root)
        if b:
            print(b.data)
        else:
            print('0')