Deicide:
Question
Given an input number n, you are to reverse the number.
E.G
Input - 12345
Output - 54321

Input - 18352
Output - 25381

Input - 2
Output - 2

naijasensei:


my_input = input("Enter a number, either 4 or 7: "

my_output = {'4': 7, '7': 4}

def is_it_4_or_7(my_var):
return my_output.get(my_var)

print(is_it_4_or_7(my_input))

naijasensei:


number = 12345

def rev_number(num):
num_str = str(num)
num_str = num_str[::-1]
out_num = int(num_str)
return out_num

print(rev_number(number))

Deicide:
Question
Given an input number n, you are to reverse the number.
E.G
Input - 12345
Output - 54321

Input - 18352
Output - 25381

Input - 2
Output - 2

cbrass:


Solved
NB: please disregard that comment on line 170 , i forgot to remove it when i was testing

Deicide:
You are correct but can you think of a faster way to do it? Since we dealing with Algorithm......one way I can think of is to push into stack and pop it out back, that way it'll come out in reverse other.

Deicide:
Correct but this code would be very slow & again Python is is a very slow language

naijasensei:


How about Kotlin then, with two(2) different implementations.

const reverse = (a) => {
let val = String(a), result = '';

for (let i = val.length - 1; i >= 0; i--) {
result += val[i];
}

return +result;
}

naijasensei:


my_input = input("Enter a number, either 4 or 7: "

my_output = {'4': 7, '7': 4}

def is_it_4_or_7(my_var):
return my_output.get(my_var)

print(is_it_4_or_7(my_input))

airsaylongcome:


Case-Switch as I know them. Would be nice if you guys can indicate what language you want the solution in. Some of us are from the very old school of programming. I'm talking BASIC and Pascal and even LISP

Deicide:
Question Given an input number n, you are to reverse the number. E.G Input - 12345 Output - 54321
Input - 18352 Output - 25381
Input - 2 Output - 2

Deicide:
Yeah kotlin is very fast

Karleb:


Why is everyone converting the input to string?

Am I missing something?

Karleb:


Why is everyone converting the input to string?

Am I missing something?

cbrass:


is it the language you are most concerned about or the method used ?

by the way can we see your own solution

Deicide:
The method used, though language used also play an important role.....You could also use module arithmetic to solve this, I think that's the fastest way to solve this.

Deicide:
The method used, though language used also play an important role.....You could also use module arithmetic to solve this, I think that's the fastest way to solve this.

naijasensei:


Modulo arithmetic, using the remainder of a division combined with the quotient. Because, given any integer, n:

n / divisor = quotient * divisor + remainder.

If 10 is our divisor (because it will preserve the number but shift the decimal point to the left, 123/10 = 12.3):

Then, n / 10 = quot * 10 + rem. For example, 12345 / 10 = 1234 * 10 + 5. If we divide by 10 repeatedly until we get zero and store the remainder in a variable during each iteration, we can successfully reconstruct the number in reverse by adding the remainders while remembering to multiply each digit by their corresponding powers of 10.

reversedNumber = (((rem1 * 10 + rem2) * 10 + rem3) * 10) + ... + remn

Image1 - Python
Image 2 - Kotlin

naijasensei:


Modulo arithmetic, using the remainder of a division combined with the quotient. Because, given any integer, n:

n / divisor = quotient * divisor + remainder.

If 10 is our divisor (because it will preserve the number but shift the decimal point to the left, 123/10 = 12.3):

Then, n / 10 = quot * 10 + rem. For example, 12345 / 10 = 1234 * 10 + 5. If we divide by 10 repeatedly until we get zero and store the remainder in a variable during each iteration, we can successfully reconstruct the number in reverse by adding the remainders while remembering to multiply each digit by their corresponding powers of 10.

reversedNumber = (((rem1 * 10 + rem2) * 10 + rem3) * 10) + ... + remn

Image1 - Python
Image 2 - Kotlin

Donpre:

Beautiful but....

naijasensei:


Nice observation. There are several things at play here. Your Python interpreter stripped off the leading zero on your text input immediately you cast your input to type int, you can confirm this. If you try to supply an int with a leading zero, your program will not run because it is not a valid int.
The main issue I see is, if zero(0) is the last digit on the integer you inputed - it will not appear in your reversed integer. This is because, you will end up having zero as your first integer digit - which is not valid.
Therefore, when this solution is used - any integer input that has a zero as the last digit will not produce an integer output with a leading zero.

Brukx:
Let's see your solution.

Karleb:
Question. Write a function that determines if a word is a palindrome.

Hint: Palindromes are words that has same spelling backward and forward.

E.g madam, racecar.

def checkpalindrum():
	x=input("Enter a word:" )
	a=0
	b=-1
	while x[a]==x[b]:
		length=len(x)
		a+=1
		b-=1
		if a==length:
			return x+" is a palindrom"
			
	else:
		return x+" is not a palindrom"
		

print(checkpalindrum())

Brukx:

def checkpalindrum():
 	x=input("Enter a word:" )
 	a=0
 	b=-1
 	while x[a]==x[b]:
 		length=len(x)
 		a+=1
 		b-=1
 		if a==length:
 			return x+" is a palindrom"
			
 	else:
 		return x+" is not a palindrom"
		

 print(checkpalindrum())

qtguru:
back here this is pcguru1 changed my moniker, there is an algorithm group on LinkedIn for blacks all over the world, anyone care to join, let's face it Nairaland is dead for collaboration.

cbrass:

what is the link ?