【发布时间】：2019-07-11 10:38:54
【问题描述】：
我正在尝试使用 python 解决Determining DNA Health challenge from Hackerrank。 （我必须补充一点，我对 python 3 有点陌生。还在学习这门语言）
对于测试用例 7、8 和 9，我的解决方案失败，并显示一条消息“错误答案”。
当我在本地运行以下代码时，我可以确认对于这些测试用例，我的实现产生了预期的输出。
我想知道会是什么问题。
我现在有点困惑。我的实施有问题吗？如果是这样，它为什么会为 28 个测试用例产生正确的答案，但在这 3 个测试用例上却失败了？或者它是来自 Hacker Rank 的误导性/令人困惑的结果信息，因为我碰巧知道人们从我从阅读讨论中学到的东西中发现这 3 个测试用例（7、8 和 9）有问题。
任何帮助将不胜感激。
这是我写的代码：
from bisect import bisect_left
from bisect import bisect_right
import sys
from unittest.mock import right
class TrieNode(object):
def __init__(self):
self.subnodes = {}
self.isTerminal = False
self.indexList = []
self.healthList = []
def addSubnode(self, aChar):
if (self.subnodes.get(aChar)):
return self.subnodes[aChar]
else:
newNode = TrieNode()
self.subnodes[aChar] = newNode
return newNode
def addIndexAndValue(self, index, health):
self.isTerminal = True
self.indexList.append(index)
lastHealth = 0
healthLength = len(self.healthList)
if (healthLength>0):
lastHealth = self.healthList[healthLength-1]
self.healthList.append(lastHealth + health)
def getSubnodeFor(self, aChar):
return self.subnodes.get(aChar)
def getValueForIndexes(self, startIndex, endIndex):
listSize = len(self.indexList)
if listSize < 1:
return 0
elif listSize == 1:
if startIndex <= self.indexList[0] and endIndex >= self.indexList[0]:
return self.healthList[0]
else:
return 0
else: # listSize > 1
rightInd = bisect_left(self.indexList, endIndex)
if rightInd < listSize and endIndex < self.indexList[0]:
return 0
big = 0
if rightInd >= listSize:
big = self.healthList[listSize - 1]
else:
if endIndex >= self.indexList[rightInd]:
big = self.healthList[rightInd]
else:
big = self.healthList[rightInd-1]
leftInd = bisect_left(self.indexList, startIndex)
small = 0
if leftInd >= listSize:
return 0
else:
if startIndex <= self.indexList[leftInd]:
if (leftInd > 0):
small = self.healthList[leftInd - 1]
else:
small = 0
else:
small = self.healthList[leftInd]
return big - small
class Trie(object):
def __init__(self):
self.root = TrieNode()
def getRoot(self):
return self.root
def createTrie(self, genes, healths):
for i in range(len(genes)):
node = self.root
for c in genes[i]:
node = node.addSubnode(c)
node.addIndexAndValue(i, healths[i])
def calculateHealth(trie, d, first, last):
total = 0
dLength = len(d)
for i in range(0, dLength):
node = trie.getRoot()
for j in range(i, dLength):
node = node.getSubnodeFor(d[j])
if node != None:
if node.isTerminal:
val = node.getValueForIndexes(first, last)
total = total + val
else:
break
return total
def readFromFile(aFileName):
inputArr = None
with open('../hackerRank/src/' + aFileName, encoding='utf-8') as aFile:
inputArr = aFile.read().splitlines()
return inputArr
def runFor(fileName, minimumValue, maximumValue):
inp = readFromFile(fileName)
n = inp[0]
genes = inp[1].rstrip().split()
healths = list(map(int, inp[2].rstrip().split()))
trie = Trie()
trie.createTrie(genes, healths)
s = int(inp[3])
minVal = sys.maxsize
maxVal = -1
for fItr in range(s):
line = inp[fItr+4].split()
first = int(line[0])
last = int(line[1])
d = line[2]
val = calculateHealth(trie, d, first, last)
if val < minVal:
minVal = val
if val > maxVal:
maxVal = val
print (minVal,maxVal)
assert minimumValue == minVal
assert maximumValue == maxVal
# TextX.txt 's are simple text files, which hold test data for regarding test case
# following the file name are real expected numbers for each relevant test case
# I got those from hacker rank
runFor('Test2.txt', 15806635, 20688978289)
runFor('Test7.txt', 0, 7353994)
runFor('Test8.txt', 0, 8652768)
runFor('Test9.txt', 0, 9920592)
runFor('Test33.txt', 11674463, 11674463)
【问题讨论】：
-
正如他们在讨论中强调的那样，可能使用了太多内存。
-
@user58697 感谢您的回复。正如您所指出的，Hacker Rank 期望解决方案在预定义的内存大小和预定义的时间段内运行。如果任何解决方案超出了这些预期，则应该给出“因超时而终止”错误，而不是“错误答案”消息。请参考support.hackerrank.com/hc/en-us/articles/…。但我 100% 确定吗？不是真的：\这就是我问这个问题的原因。
标签： python python-3.x algorithm computer-science