葫芦娃问题的一种解法，利用贪心法和本地搜索，可以得到较好的局部最优解(There are N calabash brothers numbered with 1, 2, ..., N. Each of them has a skill, which they may choose to use or not. So each of them has two states: positive if he uses the skill and negative if not. For example, if K uses his skill, his state is +K, otherwise -K. When the N brothers come together, they can transform into a new calabash brother called the Diamond brother, numbered with 0. Diamond is a fusion of the N brothers and is incredibly powerful, though he has no skill and only one state 0. Once transformed into Diamond, the N brothers can no longer change their states. The power of Diamond depends on the states of the N brothers in the following complicated way.)