自我修养►数据结构与算法

找出链表的中点

python实现:

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class Node:
    def __init__(self, data, next):
        self.data = data
        self.next = next

def find_mid_of_list(head):
    quick, slow = head, head
    i, j = 1, 2

    while quick is not None:
        while j:
            quick = quick.next
            if quick is None:
                break j -= 1

        if j == 2:
            return [slow]
        elif j == 1:
            return [slow, slow.next]

        while i:
            slow = slow.next
            if slow is None:
                break i -= 1
        i, j = 1, 2

    return None

if __name__ == "__main__":
    import sys
    import os
    if len(sys.argv) < 2:
        print("useage:%s <num_list>" % sys.argv[0])
        os._exit(-1)

    t = sys.argv[1]
    head = None
    for c in t:
        node = Node(c, None)
        node.next = head
        head = node

    for x in find_mid_of_list(head):
        print(x.data)