So this is an implementation for hash table https://www.programiz.com/dsa/hash-table that we took in class but I couldn't understand it. I have some question
- Is this like an array of size 10, like we have 10 bucket. we don't have built-in array in python so we do it with list right? this has nothing to do with 2 dimensional or something like that?
hashTable = [[],] * 10
- the if checks the number if it's even convert it to an odd number I get that, but don't get the while part why if the number is not prime we add 2 to it. does this grantee to get a prime number like if the number is odd and not prime we add 2 to it?
def getPrime(n):
if n % 2 == 0:
n = n + 1
while not checkPrime(n):
n += 2
return n
- Can't get the logic behind this function at all,
why we send a fixed number like 10 to the getPrime function? where this number came from?
and doesn't that always give us the same return value?
what we mean by the return value is the capacity?
and why we divide the key by the capacity and get the remainder of it to be the index value of the hash table
def hashFunction(key):
capacity = getPrime(10)
return key % capacity
this is the code if it helps to look at it. any addition information about explaining about the code will be much appreciated.
# Python program to demonstrate working of HashTable
hashTable = [[],] * 10
def checkPrime(n):
if n == 1 or n == 0:
return 0
for i in range(2, n//2):
if n % i == 0:
return 0
return 1
def getPrime(n):
if n % 2 == 0:
n = n + 1
while not checkPrime(n):
n += 2
return n
def hashFunction(key):
capacity = getPrime(10)
return key % capacity
def insertData(key, data):
index = hashFunction(key)
hashTable[index] = [key, data]
def removeData(key):
index = hashFunction(key)
hashTable[index] = 0
insertData(123, "apple")
insertData(432, "mango")
insertData(213, "banana")
insertData(654, "guava")
print(hashTable)
removeData(123)
print(hashTable)
