链表的部分翻转

对于一个链表，将他从第m个位置到第n个位置翻转

如 1 ——>2------->3---------->4------->5翻转为1-------->3--------->2-------->4------->5

class Node():
    def __init__(self,x):
        self.value = x
        self.next_p = None

 

def reverse(A, m, n):
    begin = A
    for i in range(m-2):
        begin = A.next_p
    head = begin.next_p
    if m == 1:
        head = begin
    p = head
    for j in range(m, n):
        temp = p.next_p
        p.next_p = temp.next_p
        temp.next_p = head
        head = temp
    if m != 1:
        begin.next_p = head
    else:
        A = head
    return A