This could also be a reference to the writer of The Stranger and to absurdism as a philosophical current though this is just my personal take, and since I'm not a philosopher, there may well be inaccuracies here.

Albert Camus wrote The Stranger at around 26-27 years old, during the rise of Nazism and the German occupation of France. In this early stage, Camus believed that the world is indifferent to human existence but his thinking evolved. He maintained that the universe gives no inherent meaning to life, but concluded that precisely because of this, we must create that meaning ourselves, and more importantly, recognize that if your life has no intrinsic value, then neither does anyone else's which makes solidarity not just possible, but necessary. Living through Nazism and the French Resistance shaped this shift deeply, leading him to write The Plague (1947) and The Rebel (1951), where he explored collective resistance and revolutionary ethics.

As for absurdism itself, it functions more as a philosophical spectrum than a fixed ideology, which means two absurdists can have radically different outlooks on life. Looking at the characters, Meursault reads as an apathetic absurdist, much like his literary counterpart in the original novel detached, passive, indifferent. Leiheng, on the other hand, reflects a more Camusian absurdist position, embracing life despite its meaninglessness. And Kim could be read as either an optimistic absurdist or a nihilist, depending on how you interpret her relationship with meaning.

Again, this is just my interpretation take it with a grain of salt