python动态规划背包问题_01背包问题python（使用递归和动态规划）

1、使用递归方法

yuanzhen@ubuntu:~/P_script$ cat mine_dp_1.py

#!/usr/bin/env python

def get_file(file_in):

fd_list=[]

f_in=open(file_in,"r")

for l_raw in f_in:

line=l_raw.strip().split(" ")

fd_list.append([int(x) for x in line]);

f_in.close()

return fd_list

def init(fd_list):

pNeed_list=[]

Gold_list=[]

for p,g in fd_list[1:]:

pNeed_list.append(p)

Gold_list.append(g)

return pNeed_list, Gold_list

def getMaxGold(people, mineNum):

if (people, mineNum) in set(sumGold.keys()):

retgold=sumGold[(people,mineNum)]

elif mineNum==0:

if people>=peopleNeed[mineNum]:

retgold=Gold[mineNum]

else:

retgold=0

else:

if(people>=peopleNeed[mineNum]):

retgold=max(getMaxGold(people,mineNum-1), getMaxGold(people-peopleNeed[mineNum], mineNum-1)+Gold[mineNum])

else:

retgold=getMaxGold(people,mineNum-1)

sumGold[(people, mineNum)]=retgold

return retgold

def main():

file_in="/home/yuanzhen/P_script/01beibao/beibao0.in"

fd_list=get_file(file_in)

print fd_list

peopleTotal=fd_list[0][0]

mine=fd_list[0][1]

global sumGold, peopleNeed, Gold

sumGold={}

peopleNeed,Gold=init(fd_list)

print peopleTotal, mine

print peopleNeed

print Gold

maxgold=getMaxGold(peopleTotal, mine-1)

print maxgold

main()

#################################

2、动态规划方法

yuanzhen@ubuntu:~/P_script$ cat mine_dp_2.py

#!/usr/bin/env python

def get_file(file_in):

fd_list=[]

f_in=open(file_in,"r")

for l_raw in f_in:

line=l_raw.strip().split(" ")

fd_list.append([int(x) for x in line]);

f_in.close()

return fd_list

def init(fd_list):

pNeed_list=[]

Gold_list=[]

for p,g in fd_list[1:]:

pNeed_list.append(p)

Gold_list.append(g)

return pNeed_list, Gold_list

def getMaxGold(people, mine):

for people_i in range(0,people+1):

for mine_j in range(mine+1):

people_num=peopleNeed[mine_j]

if mine_j==0:

if people_i>=people_num:

sumGold[(people_i, mine_j)]=Gold[mine_j]

else:

sumGold[(people_i, mine_j)]=0

else:

if people_i>=people_num:

sumGold[(people_i, mine_j)]=max(sumGold[(people_i-people_num, mine_j-1)]+Gold[mine_j], sumGold[(people_i,mine_j-1)])

else:

sumGold[(people_i, mine_j)]=sumGold[(people_i, mine_j-1)]

return sumGold[(people, mine)]

def main():

file_in="/home/yuanzhen/P_script/01beibao/beibao0.in"

fd_list=get_file(file_in)

print fd_list

peopleTotal=fd_list[0][0]

mine=fd_list[0][1]

global sumGold, peopleNeed, Gold

sumGold={}

peopleNeed,Gold=init(fd_list)

print peopleTotal, mine

print peopleNeed

print Gold

maxgold=getMaxGold(peopleTotal, mine-1)

print maxgold

main()

########################################

输出结果

[[100, 5], [77, 92], [22, 22], [29, 87], [50, 46], [99, 90]]

100 5

[77, 22, 29, 50, 99]

[92, 22, 87, 46, 90]

133