单选题：Consider a special queue which is a linear structure that allows

Consider a special queue which is a linear structure that allows insertions at one end, yet deletions at both ends. Given an insertion sequence { 42, 36, 21, 63, 16 }. Which of the following is NOT a possible deletion sequence?




A.16 42 21 36 63
B.42 21 36 16 63
C.36 21 42 63 16
D.21 16 42 63 36


答案：A