java - How to write this function?

Question

Write a method/function, called queues2stack, in pseudocode (or Java without using specialised libraries) that receives two queues and creates a single stack that contains all the information from each of the queues. Each of the two input queues contains a set of integers and is ordered by having the integers in decreasing order (highest at the front of the queue, lowest at the end). Your algorithm should always add the highest valued entries. The resulting stack will have the same number of entries as the sum of the number of entries in the two queues.

What I've written:

void queues2stack {
  while (!q1.empty & q2.empty) {    
    if (q1.pop () > q2.pop()) 
      s.push(q1.pop)
    else 
      s.push(q2.pop)
  }
    
  while (!q1.empty()) {
    s.push(q1.pop)
  }
  
  while !q2.empty() {
    s.push(q2.pop)
  }
}

Answer 1

Use peek() to check the values without removing them.

void queues2stack {
  while (!q1.empty & q2.empty) {    
    if (q1.peek() > q2.peek()) 
      s.push(q1.pop())
    else 
      s.push(q2.pop())
  }
    
  while (!q1.empty()) {
    s.push(q1.pop)
  }
  
  while !q2.empty() {
    s.push(q2.pop)
  }
}