環狀佇列的基本運作

(1)

環狀佇列的

(2)

範例

假設環狀佇列的大小是6, add ( ) 函數會將資料加入佇列

中，delete ( ) 函數會從佇列中取出一資料。若有一主程

式如下，請寫出printf ( ) 函數執行的結果。

void main()

{

add(10);

add(20);

add(30);

add(delete()+40);

printf(“%d\n”, delete());

printf(“%d\n”, delete()-delete());

}

(3)

解:

3 rear 2 1 4 5 0 rear 0 rear front = 5 = 0 1 2 3 10 4 5 10 front

(1) add(10);

(2) add(20);

3 rear 2 1 4 5 0 rear 1 rear front = 5 = 0 1 2 3 10 4 5 10 front 20 20

(4)

(3) add(30);

(4) add(delete()+40);

3 rear 2 1 4 5 0 rear 2 rear front = 5 = 0 1 2 3 10 4 5 10 front 20 20 30 30 3 rear 2 1 4 5 0 rear 3 rear front = 0 = 0 1 2 3 4 5 front 20 20 30 30 50 50 front

(5)

(5) printf(“%d\n”, delete());

印出

20 (6) printf(“%d\n”,delete()-delete());

印出

30-50 =

-20

3 rear 2 1 4 5 0 rear 3 rear front = 1 = 0 front1 2 3 4 5 30 30 50 50 front 3 rear 2 1 4 5 0 rear 3 rear front = 3 = 0 1 2 3 4 5 front front