贪婪算法
这时候有人会问，不是最准确的答案我要她干嘛？但是在日常中，我们有时候会遇到一些我们无法处理的问题，甚至是要花费成吨的资源也无法很好解决的问题
假如我们现在很富有，家里有好多地皮造房子，这时候你需要找最少的施工队伍去帮我们同时造房子
现在一共有4个施工队伍，每个队伍负责的区域如下我放在一个字典里
house_haved =set( ["杨浦","徐汇","崇明","虹口","黄浦","普陀","闵行","宝山"] ) constructionTeam = {"one":set(["杨浦","徐汇","崇明"]),"two":set(["崇明","虹口","黄浦"]),"three":set(["虹口","黄浦"]),"four":set(["虹口","普陀","闵行","宝山"])}
创建一个用过存放最终结果的集合
final_teams=set()
循环取队伍判断能覆盖最多未覆盖的地区的队伍
取house_haved和team_cover的交集和best_covered比较， 循环出best_covered
while house_haved :
best_team=None
best_covered = set()
for team , team_cover in constructionTeam.items():
covered = house_haved & team_cover
if len(covered) > len(best_covered):
best_team = team
best_covered = covered
final_teams.add(best_team)
house_haved -= best_covered