while(!stack.isEmpty() && asteroid<0 && stack.peek()>0){
  
   if(stack.peek()>Math.abs(asteroid)
   {
      break;
   }
   else if(Math.abs(asteroid)>stack.peek())
  {
     stack.pop();
    
  }else{
    stack.pop();
    break;     
  }

}

if(stack.isEmpty() || asteroid>0 || stack.peek()>0)
  stack.push(asteroid)
========================================================
class Solution {
    public int[] asteroidCollision(int[] asteroids) {
        Stack<Integer> stack=new Stack<>();   
        boolean found=false;
        for(int i=0;i<asteroids.length;i++){
            int x=asteroids[i];
            found=false;
            while(!stack.isEmpty() && x<0 && stack.peek()>0){
                if(stack.peek()>Math.abs(x)){
                    break;
                }else if(stack.peek()<Math.abs(x)){
                    stack.pop();
                }else{
                    stack.pop();
                    found=true;
                    break;
                }
            }
            if(found==false){
                if(stack.isEmpty() || x>0 || stack.peek()<0){
                    stack.push(x);
                }
            }
        }
        int c=0;
        int ans[]=new int[stack.size()];
        for(Integer i:stack){
            ans[c]=i;
            c++;
        }
        return ans;
    }
}
===============================================================