Okay, so I've been working on this for a while, to no avail, and was wondering if anyone can help.

I believe it's fairly simple but my brain is apparently numb to this sort of logic...

I need to print the following numbers out in this exact format:

121
12321
1234321
123454321
12345654321
1234567654321


I need to use 3 for-loops, 2 nested within 1 the outer for-loop.

In this sort of fashion:




Any help would be much appreciated!
Keep in mind, the variables' increments could be anything in the 2 nested for-loops.
The outer for-loop controls how many lines that's going to be printed (in this case, 6)
The second, im guessing, controls the first number of each line, (1) and the numbers between the max number in each line and the last number in each line (2, 3, 4, 5, 6, 7 respectively)
While the last controls the max number in each line, BUT I really am not 100% sure

This post was edited by DD_Rocking on Sep 17 2014 03:40pm

what is the problem you're facing?

this is how i'd approach the problem:

1) given n, figure out how to write out 1, 2, ..., n - 1, n
eg: given 4, write out 1234

2) given n, figure out how to write out 1, 2, ..., n -1, n, n - 1, .... 2, 1
eg: given 4, write out 1234321

3) given n, figure out how to write out 1, 2, ..., n -1, n, n - 1, .... 2, 1 and then put a new line at the end
eg: given 4, write out 1234321\n

4) assuming the above is done, loop it from 2 to n

do it in this order. don't try to set up all the loops at once, and everything is wrecked. you want to be able to show progress at each step so you can understand it and narrow down where the problem is

this NEEDS to be written in 3 for-loops
and cannot use any other variables than ones declared and initialized within the for-loops

so, I would guess this would have to compare the variable in the 2nd for-loop to the variable in the first for-loop in some way in order to print the first number, then any following on each line
then compare the variable in the third to the second or first

this is where I am sort of lost

If I was able to, I would just use print statements with extra variables, id simply assign new variables and print them: var1 = 1, var2 = 2, var3 = 3, etc.

This post was edited by DD_Rocking on Sep 17 2014 04:08pm

following my procedure, i was able to get it done to your teacher's satisfaction without even looking at your requirements. steps 1 and 2 are the two inner loops, step 4 is the outer loop.

so how about you show me your code from step 1, step 2, step 3, and step 4? if it doesn't fit your assignment's requirements, we'll work on it.


This post was edited by carteblanche on Sep 17 2014 04:18pm

well, its not really an assignment, my prof said it is extra credit on the exam I will be taking in a few hours

anyway, here's what I've got, keep in mind, this is completely incorrect in some aspects.



I am confused how I would go about getting it to print each number in between the max number and the end, including the end

So far, I've been able to get it to print 121 on a single line, but adding more lines causes it to print incorrectly
Also, I've been able to get it to print 1, 12, 123, 1234, etc. on each line for 6 lines (last line = 123456)

This post was edited by DD_Rocking on Sep 17 2014 04:19pm

your instructions are slightly conflicting.


the way that's worded, the code should look like this:


which is different from your sample. what did your teacher give you, precisely?

regardless, how about you write code specifically for each of my 4 steps that i listed? then we'll go from there.

This post was edited by carteblanche on Sep 17 2014 04:20pm

It was just a question that was on our practice exam
then he went over the example in-class, but doesn't post the answers, and I wasn't able to get it written down in its entirety

but, basically he did this:

on #2, how would I do 1234321 in 1 for loop?
I can do 1234
like this:

for(int i = 1; i <= 4; i++)
{
System.out.print(i);
}

Thats no problem, but how would I now go about going from 3 to 1 on the same line? Would I utilize the other for loop to write it on the same line but going from i (while it's 4) down to 1?

I could understand that

Here's what I've got thus far:



Output:

121
1232
12343
123454
1234565
12345676


The problem is that I can't get the remaining numbers at the end print...

couple suggestions.

1) stop worrying about the outer loop and just focus on the two inner loops to create 1 line of output.

replace your outer loop with just this:

int i = 7;

2) if you're having a problem with a specific loop, then write the code WITHOUT loops.

ex: instead of something like this:
for (int j = 0; j < 4; j++){
print(j);
}

you would write this:

print(0);
print(1);
print(2);
print(3);

then once you get the exact output you want, look at the numbers you had to use and figure out the loop that makes it