Implementing queue in java

Question

Implementing a queue in Java is pretty common interview question. I surfed online and saw many implementations where they do fancy stuff like implementing queue interface and wr

Answer 1

One way is to maintain an array of items q and two indices to the head and the tail of the queue (initially set to 0). Pseudo-code follows:

enqueue(x)
{   q[tail++] = x;
}

dequeue()
{   return q[head++];
}

If the array overflows, you double the size and reinsert the items. This yields O(1) amortized time per operation. Another approach is to use a linked list (which you should implement) and again store a pointer to the head and a pointer to the tail.