本帖最后由 zooo 于 2016-5-4 00:08 编辑
思路:根据题意数组中每个元素都有4个方向
定义一个函数用来找出每个元素在这4个方向的最大值,遍历整个矩阵后找出最终结果
from functools import reduce
import time
def find_max_eachElem(numArr, x, y):
aspect = [[], [], [], []]#对数组中每个元素的四个方向初始化
for i in range(4):
if 0<= y+i <20:
aspect[0].append(numArr[x][y+i])#右
else:aspect[0].append(0)
if 0<= x + i <20 and 0<= y + i <20:
aspect[1].append(numArr[x + i][y + i])#右下
else:aspect[1].append(0)
if 0<= x+i <20:
aspect[2].append(numArr[x + i][y])#下
else:aspect[2].append(0)
if 0<= x - i and 0<= y + i <20:
aspect[3].append(numArr[x - i][y + i])#左下
else:aspect[3].append(0)
max, maxArr = 0, []
for arr in aspect:
tmp = reduce(lambda x, y:x*y, arr)
if tmp > max:
max, maxArr = tmp, arr
return (max, maxArr)
s = time.time()
str_num = '''08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08
49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00
81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65
52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91
22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80
24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50
32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70
67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21
24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72
21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95
78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92
16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57
86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58
19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40
04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66
88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69
04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36
20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16
20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54
01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48'''
numArr = list(map(lambda x:list(map(lambda y:int(y), x.split())), str_num.split('\n')))
max = 0
for x in range(20):
for y in range(20):
if numArr[x][y]: #跳过0
result = find_max_eachElem(numArr, x, y)
if result[0] > max:
(max, maxArr) = result
print(max, maxArr, time.time()-s)
并行代码(使用pp模块),由于计算规模太小效率反而下降了,实验计算400x400的数组效率明显提升
并行计算数组400x400.zip
(171.36 KB, 下载次数: 0)
import pp
import functools
def find_max_eachElem(numArr, x, y):
aspect = [[], [], [], []]#对数组中每个元素的四个方向初始化
for i in range(4):
if 0<= y+i <20:
aspect[0].append(numArr[x][y+i])#右
else:aspect[0].append(0)
if 0<= x + i <20 and 0<= y + i <20:
aspect[1].append(numArr[x + i][y + i])#右下
else:aspect[1].append(0)
if 0<= x+i <20:
aspect[2].append(numArr[x + i][y])#下
else:aspect[2].append(0)
if 0<= x - i and 0<= y + i <20:
aspect[3].append(numArr[x - i][y + i])#左下
else:aspect[3].append(0)
max, maxArr = 0, []
for arr in aspect:
tmp = functools.reduce(lambda x, y:x*y, arr)
if tmp > max:
max, maxArr = tmp, arr
return (max, maxArr)
def findMax(numArr, beg, end):
max = 0
for x in range(beg, end):
for y in range(20):
if numArr[x][y]: #跳过0
result = find_max_eachElem(numArr, x, y)
if result[0] > max:
(max, maxArr) = result
return (max, maxArr)
str_num = '''08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08
49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00
81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65
52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91
22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80
24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50
32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70
67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21
24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72
21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95
78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92
16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57
86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58
19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40
04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66
88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69
04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36
20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16
20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54
01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48'''
numArr = list(map(lambda x:list(map(lambda y:int(y), x.split())), str_num.split('\n')))
funList = []
#开启pp服务
job_server = pp.Server(ncpus=2)#使用2个核心
#分4段
parts = 4
step = 20//4
for index in range(4):
funList.append(job_server.submit(findMax, (numArr, index*step, (index+1)*step),
(find_max_eachElem, ), ('functools', ) ))
listResults = []
for fun in funList:
listResults.append(fun())
dictResults = dict(listResults)
job_server.print_stats()
maxNum = max(dictResults.keys())
print(maxNum, dictResults[maxNum])
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