Asteroid Collision LeetCode solution in JavaScript

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/**
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 * @param {number[]} asteroids
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 * @return {number[]}
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 */
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var asteroidCollision = function (asteroids) {
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  const s = [];
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  for (let i = 0; i < asteroids.length; i++) {
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    const a = asteroids[i];
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    // Negative asteroids to the left of the stack can be ignored.
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    // They'll never collide. Let's just add it to the answer stack and
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    // move on. I consider this a special case.
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    if ((s.length === 0 || s[s.length - 1] < 0) && a < 0) {
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      s.push(a);
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      // If an asteroid a is positive (l to r), it may still collide with an
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      // a negative asteroid further on in the asteroids array
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    } else if (a > 0) {
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      s.push(a);
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      // a is negative. It can only collide with positive ones in
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      // the stack. The following will keep on iterating
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      // until it is dealt with.
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    } else {
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      const pop = s.pop();
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      // positive pop beats negative a, so pick up pop
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      // and re-add it to the stack.
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      if (Math.abs(pop) > Math.abs(a)) {
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        s.push(pop);
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        // a has larger size than pop, so pop will get dropped
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        // and we'll retry another iteration with the same
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        // negative a asteroid and whatever the stack's state is.
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      } else if (Math.abs(pop) < Math.abs(a)) {
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        i--;
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        // magnitude of positive pop and negative a are the same
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        // so we can drop both of them.
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      } else {
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        continue;
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      }
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    }
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  }
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  // The stack should be the answer
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  return s;
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};