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  1. #include<stdio.h>
  2.  
  3. #define SIZE 5
  4. int queue[SIZE];
  5. int head, tail;
  6.  
  7. void enqueue(int value);
  8. int dequeue(void);
  9.  
  10. int main(void)
  11. {
  12.     head = tail = 0; 
  13.     int data, i;
  14.  
  15.     enqueue(1);
  16.     enqueue(2);
  17.     dequeue();
  18.     enqueue(3);
  19.     dequeue();
  20.     enqueue(4);
  21.     enqueue(5);
  22.     dequeue();
  23.     enqueue(6);
  24.  
  25.     for(i=0; i<SIZE; i++){
  26.       printf("queue[%d]=%d\n", i, queue[i] );
  27.     }
  28.  
  29.     return 0;
  30. }
  31.  
  32. void enqueue(int value)
  33. {
  34.     if ((tail + 1) % SIZE == head) {
  35.         // 満杯なので何もしない
  36.         return;
  37.     }
  38.     queue[tail] = value;
  39.     tail = (tail + 1) % SIZE;
  40. }  
  41.  
  42.  
  43.  
  44.  
  45. int dequeue(void)
  46. {
  47.     int value;
  48.     if (head == tail) {
  49.         // 空なのでエラー値返す
  50.         return -1;
  51.     }
  52.     value = queue[head];
  53.     queue[head] = 0; // 初期値 0 を代入
  54.     head = (head + 1) % SIZE;
  55.     return value;
  56. }
  57.  
  58.  
  59.  
Success #stdin #stdout 0s 5324KB
comments (?)
stdin 
Standard input is empty
stdout 
queue[0]=6
queue[1]=0
queue[2]=0
queue[3]=4
queue[4]=5
https://ideone.com/qEMSOh
language:
C (gcc 8.3)
created:
11 days ago
visibility:
public

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