贪心算法

#会议类
class meet:
    num=0
    begin=0
    end=0

#所有会议
meets=[]

#初始化会议列表
m=meet()
m.num=1
m.begin=8
m.end=10
meets.append(m)

m=meet()
m.num=2
m.begin=9
m.end=11
meets.append(m)

m=meet()
m.num=3
m.begin=10
m.end=15
meets.append(m)

m=meet()
m.num=4
m.begin=11
m.end=14
meets.append(m)

m=meet()
m.num=5
m.begin=13
m.end=16
meets.append(m)

m=meet()
m.num=6
m.begin=14
m.end=17
meets.append(m)

m=meet()
m.num=7
m.begin=15
m.end=17
meets.append(m)

m=meet()
m.num=8
m.begin=17
m.end=18
meets.append(m)

m=meet()
m.num=9
m.begin=18
m.end=20
meets.append(m)

m=meet()
m.num=10
m.begin=16
m.end=19
meets.append(m)

import operator

selectmeets=[] #选择参与的会议

def selectmeet(meetlist):
    cmpfun = operator.attrgetter(‘end‘) #按照end进行排序
    meetlist.sort(key = cmpfun)
    selectmeets.append(meetlist[0]) #先选第一个会议
    endtime=meetlist[0].end #会议结束时间
    for i in range(1,len(meetlist)):
        if endtime<=meetlist[i].begin: #如果结束时间小于该会议的起始时间
            selectmeets.append(meetlist[i])
            endtime=meetlist[i].end
   

selectmeet(meets)  

for obj in selectmeets:
    print(obj.num)       

‘‘‘打印结果为：    
1
4
6
8
9
‘‘‘

#商品类
class good:
    name="" #商品名
    weight=0  #重量
    price=0   #价格
    p=0  #性价比

goods=[]

g=good()
g.name="手表"
g.weight=2
g.price=85
g.p=g.price/g.weight
goods.append(g)

g=good()
g.name="剃须刀"
g.weight=3
g.price=60
g.p=g.price/g.weight
goods.append(g)

g=good()
g.name="西瓜"
g.weight=5
g.price=10
g.p=g.price/g.weight
goods.append(g)

g=good()
g.name="篮球"
g.weight=1.5
g.price=30
g.p=g.price/g.weight
goods.append(g)

g=good()
g.name="可乐"
g.weight=1
g.price=3.5
g.p=g.price/g.weight
goods.append(g)

g=good()
g.name="香烟"
g.weight=2.5
g.price=75
g.p=g.price/g.weight
goods.append(g)

g=good()
g.name="茅台"
g.weight=1.2
g.price=240
g.p=g.price/g.weight
goods.append(g)

g=good()
g.name="烤鸡"
g.weight=2.2
g.price=22
g.p=g.price/g.weight
goods.append(g)

g=good()
g.name="相机"
g.weight=2
g.price=2000
g.p=g.price/g.weight
goods.append(g)

g=good()
g.name="袜子"
g.weight=1
g.price=12
g.p=g.price/g.weight
goods.append(g)

import operator

selectgoods=[]  #挑选的商品

def selectgood(goodlist):
    cmpfun=operator.attrgetter(‘p‘) #按性价比排序
    goodlist.sort(key=cmpfun,reverse=True)
    residueweight=12 #背包剩余承重空间
    for obj in goodlist:
        if residueweight>=obj.weight: #如果总重小于背包承重
             selectgoods.append(obj)
             residueweight=residueweight-obj.weight
  

selectgood(goods)
for obj in selectgoods:
    print(obj.name)

‘‘‘打印结果为：
相机
茅台
手表
香烟
剃须刀
袜子
‘‘‘