Compare if two arrays have same characters in reverse order. (C++)

Question

1.00/5 (2 votes)

See more:

int isReverse (char array_a[], char array_b[], int size) {

}

//I know how to do the compare part but I'm stuck on the reverse order part
// I'm don't know how to check char arrays if they have the same character in reverse order

What I have tried:

int isReverse (char array_a[], char array_b[], int size) {

for (int i=0; i < size; i++)
{
if (array_a[i] != array_b[i])
return false;
else
return true;
}

Posted 8-Oct-18 16:20pm

codingBlonde

Updated 8-Oct-18 20:37pm

Add a Solution

3 solutions

Solution 3

missing tips:
a) use an extra downcounter which starts at the last element
b) one difference means the result is false, BUT true only when all done
c) write some test data to call your function

Posted 8-Oct-18 20:37pm

KarstenK

Comments

CPallini 9-Oct-18 4:06am

My 5.

Solution 2

Think abut it: it's not complicated.
Start by checking the lengths: if they are different, they don't match.
It that's fine, compare the last element of one array with the first element of the other. That's easy x[0] vs y[0 + len - 1]
If they are the same, compare the last but one element of one array with the second element of the other. That's easy x[1] vs y[1 + len - 1]
And so on, until you have done them all.

And a little bit of thought will show you how to do that in a loop ...

Posted 8-Oct-18 19:37pm

OriginalGriff

Comments

CPallini 9-Oct-18 4:06am

My 5.
Given the function signature, the OP cannot check the lengths of the array.

OriginalGriff 9-Oct-18 4:17am

Given that they are char arrays, chances are they are null terminated strings. If not, he needs to supply the length(s) or it can't be done!

CPallini 9-Oct-18 4:21am

Hey man, you cannot code on 'chances'. :-D

OriginalGriff 9-Oct-18 4:27am

Half of QA is coding on "guesses", so I'm allowed to code on "chances" :laugh:

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Patrice T · Accepted Answer · 2018-10-08T18:27:00

Quote:
I know how to do the compare part but I'm stuck on the reverse order part
I'm don't know how to check char arrays if they have the same character in reverse order

Take a sheet of paper and pencil and try to solve by hand.
Choose a sample, write the 2 arrays, write the position of each char, make a table with positions of chars you have to check in both arrays.
Write another example with another size.
Find the mathematical relation between the char check positions in both arrays. This is very simple maths, if you can't deal with it, have a talk with your teacher, because you have a big problem.

We do not do your HomeWork.
HomeWork is not set to test your skills at begging other people to do your work, it is set to make you think and to help your teacher to check your understanding of the courses you have taken and also the problems you have at applying them.
Any failure of you will help your teacher spot your weaknesses and set remedial actions.
Any failure of you will help you to learn what works and what don't, it is called 'trial and error' learning.
So, give it a try, reread your lessons and start working. If you are stuck on a specific problem, show your code and explain this exact problem, we might help.

As programmer, your job is to create algorithms that solve specific problems and you can't rely on someone else to eternally do it for you, so there is a time where you will have to learn how to. And the sooner, the better.
When you just ask for the solution, it is like trying to learn to drive a car by having someone else training.
Creating an algorithm is basically finding the maths and make necessary adaptation to fit your actual problem.