门| Sudo GATE 2020 Mock I（2019 年 12 月 27 日）|问题 33

考虑以下链表：

S 是头指针，P 是空指针。在这个链表中按顺序执行给定的操作：

(i) P = S → next → next → next 
(ii) P → next → next → next → next = S → next → next → next → next
(iii) S → next → next → next = P → next → next
(iv) X = S → next → next → next → next → next → next → next → data 

X 的值是多少?
(一) 5
(乙) 6
(三) 7
(D)分割错误答案： (C)
说明：按顺序执行给定的操作后，最终的链表将如下所示：

(i) P = S → next → next → next 
P = 1000 → 2000 → 3000 → 4000
 
(ii) P → next → next → next → next = S → next → next → next → next
P → 5000 → 6000 → 7000 → null = S → 2000 → 3000 → 4000 → 5000

(iii) S → next → next → next = P → next → next 
S → 2000 → 3000 → 4000 = P → 5000 → 6000 

因此，X 的值将是：

X = S → next → next → next → next → next → next → next → data 

X = 1000 → 2000 → 3000 → 6000 → 7000 → 5000 → 6000 → 7000 → 7
X = 7

所以，选项(C)是正确的。
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