说明：  核心思想：在自然界鸟群觅食过程中，我们可以想象食物自身散发某种着香味（实际上可能不是，此处仅以香味为例代表鸟群可能获得的某种食物信息），该香味距离食物越近则越浓（以状态函数值进行描述）
(Core idea: In the process of foraging birds in nature, we can imagine that food itself emits some kind of fragrance (in fact, it may not be, here just take the fragrance as an example to represent some kind of food information that the birds may get), the closer the fragrance is to the food, the stronger the fragrance is (described by the value of the state function).)