二叉树

二叉树：

定义：二叉数是一种树其结点度不能大于二

二叉树分为：满二叉树，完全二叉树，不完全二叉树，斜二叉树

二叉树的最末端是叶子结点（空树例外）

求双亲的孩子结点：（只用于完全二叉树）

a = ["A","B","C","D","E","F","G","H","I","J"]
b = input()
c = len(a)
leftchild = 0
rightchild = 0
for i in range(c):
    if b == a[i]:
        leftchild = i * 2 + 1
        rightchild = i * 2 + 2
if leftchild < c:
    print("左",a[leftchild])
elif rightchild < c:
    print("右",a[rightchild])
else:
    print("无")

通过孩子结点找双亲结点：（只用于完全二叉树）

a = ["A","B","C","D","E","F","G","H","I","J"]
b = input()
c = len(a)
shuangqin = 0
for i in range(c):
    if b == a[i]:
        shuangqin = (i - 1) // 2
if shuangqin > 0:
    print(a[shuangqin])
else:
    print("无")

讲解参考链接：

二叉树基本理论：
https://www.baidu.com/link?url=ERqapUSkEIJNcxMtqdFQ55bcab3f5Qmrfm_XmICTQOxOIOEhj-eG-F5JyPtE2mdW&wd=&eqid=df117dda000137e80000000360e92708