生物学中，顶端优势现象普遍存在。顶端优势指的是：植物的顶芽会优先声张，从而抑制侧芽的生长。如果植物的某个分叉点包括多个芽，我们通常需要摘去其中的顶芽来保证别的芽的正常生长。

算法计算了一棵树的需要摘除芽的个数。-Biology, the widespread phenomenon of apical dominance. Advantage refers to the top: Bud plants will be given a quiet, thereby inhibiting the growth of lateral bud. If a bifurcation point of the plant, including a number of shoots, we usually removed the terminal bud to ensure the normal growth of other buds. Algorithm needs a tree removed the number of buds.